Easiest bicycle to assemble? Single speed? I have an XC MTB, a road bike and a trainer, which I maintain.
I also do maintenance for the kids and wife's bikes.

Today I replaced a cassette in my road bike - something that required special tools but was rather easy.

I think I might be ready for the next level - to put a whole bike together.

I'm thinking a single speed (freewheel or switchable) would be the easiest to build, perhaps with a front brake only - get a frame, ready made wheels, hubs, chain, sprockets etc and I should be good to go?

Am I being too optimistic? What it the hardest part of building a bicycle?

I would suggest that before you decide to build a single speed/fixie consider if this is a type of bike you are likely to use when it's complete. One aspect that has to be considered is the cost of the specialty tools required for the assembly. While many enthusiasts consider the cost an investment, it is none the less an expense. Part of the problem with your first build may be determining what tools you will need prior to the actual assembly. Do you need a headset installation tool or will it be a drop-in unit. what bottom bracket type and what brand will require different tools. Will the wheels have serviceable bearings requiring special wrenches or pressed in bearings. None of this is insurmountable but can be frustrating. My suggestion is to take your time picking up components when the price and quality meet your expectations. Shop around noting the average price so you can take advantage of exceptional deals. Them acquire what ever tools you need to mount the specific component. I have done this several times and the time frames ranged from 30 days to 7 months.


What do I need to do to get bike sharing costs included as part of my commuter benefits (USA) This might be more of a discussion for politically informed people. Does anyone here know who I should contact or if there is already some groups working on this? I'd love to be able to write off my bike sharing costs in Arizona, USA, or be able to pay for it out of my Commuter savings. More information about what I'm talking about can be found at this link. http://www.thewashcycle.com/2016/06/bicycle-commuter-benefit-still-cant-be-used-for-bike-sharing.html

If your company participates or could be encouraged to participate in WageWorks (a commercial commuting-cost management company), one of the optional packages is bicycling commuting costs. WageWorks handles the pre-tax deduction and reimbursements.  Eligible expenses of up to $20/month include:

Bicycle improvements, such as handlebars, pedals, seats, tires, and other equipment that is permanently attached to the bicycle
Bicycle repairs
Bicycle purchase
Bicycle storage
Bicycle helmets

Unfortunately, bike sharing systems aren't included - and I don't think you could use the commuter transit plan (prepaid debit card) for those either, in fact your linked article makes it clear that they aren't:

In 2013, the IRS was asked if it could "adopt bike share as a qualifier for the Transportation (Commuting) Benefits program under the Fringe Benefit Exclusion Rules for transit," the same rules under which employers can give tax free transportation benefits to employees. But in July of that year, they said no, because bike share is not mass transit.  They also said that bike share was not a qualified bicycle commuting reimbursement, which one could pay with the bicycle commuter benefit, because those were specifically limited to "expenses for the purchase of a bicycle or bicycle improvements, repair or storage."
Source: http://www.thewashcycle.com/2016/06/bicycle-commuter-benefit-still-cant-be-used-for-bike-sharing.html

So at this point what you need to do is to lobby your congresscritters to amend the legislation that directs how the IRS treats commuting costs so that bike sharing is included.
Note: to my chagrin, my employer participates in WageWorks but hasn't activated the bicycling option. So even if you have wageworks, you'd have to lobby to get bicycling added to it. As an aside, I really like the subsidized commuter bicycle purchase program that London has - since you can write-off your entire bike purchase and it's good for the local economy as you do it through your local bike shop.


How to choose a bicycle seat I'll need a new saddle for my bike soon. I use it mainly for short commutes (30 minutes). About once a year I go touring for a few days, up 8 hours in the saddle.

My current saddle just came with the bike. I see there are a lot of different saddle types available now, from the ultra thin, to the wide & comfy to the downright fruity.I associate the thin saddles with racers, but thats the limit of my knowledge.

When choosing a new saddle, should I choose based on my body frame or my cycling type (i.e. get one for short commutes, one for touring)?

Choosing a saddle that fits you is very important. The wrong saddle can lead to numbness and pain in the crotch area, and in the long run serious health issues. The right saddle for you should fit comfortably regardless of what type of riding you do and will depend mainly on the width of your pelvic. Ideally you should get a professional fit. If one is not available to you, you should try a few saddles of different sizes to determine what fits you before you purchase.


Are all rear DI2 shifters / derailleurs / internal gear hubs interchangeable? I'm specifically talking about rear shifters....
Can I mix and match any of Shimano's DI2 shifters with rear derailleurs and internal geared hubs?
Shimano makes several DI2 shifters

integrated shifters for drop bars (e.g. ST-R9170, and ST-R785)
thumb shifters for flat bars (e.g. SW-M8050 and SW-M9050)
standalone buttons (e.g. SW-R600 and SW-S705)

They also make several DI2 rear derailleurs and internal geared hubs

rear derailleurs (e.g. RD-R9150 and RD-M9050-SGS)
internal geared hubs (e.g. SG-S7051-8 and SG-S7051-11)

Are all of these combinations completely compatible?
For example, can I run ST-R9170 (Dura Ace 11spd "road" integrated shifter) with SG-S7051-8 (Alfine 8sp internal geared hub)?

Looks like Shimano provides a handy guide: https://bike.shimano.com/en-EU/e-tube/project/compatibillity.html
source
Posted here since Shimano is already deleted it:


Replacement shifter for Shimano exage 7-speed - modern shifter compatible? I've got an early 1990s Schwinn Crosscut with Shimano Exage LX400 components.  I've just pulled it out of storage.  The bike is in pretty good shape overall.  The derailleurs are moving freely and the gears and cranks don't have any significant visible wear.

The front shifter ratchet mechanism was stuck.  I couldn't get in very well but i sprayed it down with WD-40 and tried to work the mechanism, but no luck.

I replaced it with a Shimano Altus SL-M310.  that is working mostly, I've got it adjusted to the point that  the chain rubs slightly on the front derailleur when on both the smallest crank and rear gear, I can live with that.

Meanwhile, the rear shifter failed while I was testing the new front shifter.  Similar ratchet mechanism stuck.

I can easily enough (hah) replace the front shifter with the matching right side SL-M310, but with 7 speeds instead of 3 there's a lot less room for error.  Is this new shifter likely to have the same distance between gears as the old derailleur?

For the shifter to match, you need to match the number of speeds, cassette width and shifter actuation ratio. For Shimano everything under 10 speeds (except 8-speed Dura Ace which most people don't have to care about) has the same actuation ratio, so all you need to know is the new shifters are 7-speed Shimano. These can still be bought.


Recommended brands for full-day rides and short multi-day tours I’m going to be investing in a new touring bike soon for weekly centuries and the occasional few-day tour. I’m looking at the $2K or possibly $3K level.

I currently ride a Lemond Croix de Fer, and I like the comments I get from others who notice I’m riding a LeMond. So I find myself wanting to look beyond the common brands like Specialized and Trek. My question: is it reasonable to look beyond the common brands for a bike that is more "specialized" than Specialized?

Specific product recommendations are off topic here, but the answer to your general question is yes, it's fine to look beyond the biggest bicycle producers (Trek Specialized, Giant, Cannondale etc.)

Surly and Salsa are two brands that offer touring oriented frames that come to mind. (Note, I offer these as examples, not recommendations).


does anyone still make competitive chromoly frames for road biking? Chromoly frames can be constructed relatively light if the quality is high enough.

Does anyone know of any brands that concentrate on making modern chromoly frames for entry level competitive cycling?  i.e. litespeed is to titanium
as x is to chromoly

Thanks!

The best place to start would be all-city:
http://www.allcitycycles.com/bikes/space_horse

or Lemonde as a second option:
https://lemond.cc/#!/bicycles


Good fit vs. Best fit - Lower end of the fit range (Difference of 1 cm). Is it OK? or can this tiny difference still cause pains? I want to buy a second hand Trek Cronus (Gary Fischer Collection) bike (50cms) for my wife. I am getting a good deal on it. My wife's height is 156cms. As per the Trek Sizing chart, the range of rider height for a 50cms bike is from 157cms to 165cms. So technically the perfect fit for 50cms looks like 161cms.

So, my query is that would a 1 cm difference (her height of 156cms vs fit starting from 157cms) matter in causing any kind of pains (knee, back etc.) for her in the long run for her? I would ideally like her to go for her perfect fit of 47cms Trek bike. However, this second hand carbon fiber bike with Shimano 105 components is priced at the same rate as a new Trek One series 1.1 with a Shimano Claris components. That's the main pull.

Also, on a side note, how is the Trek Cronus (Gary Fischer Collection) bike? I tried to read reviews. But I did not find many for this particular model as I found for the regular Domanes, Emondas etc.

I tried to search the site if a similar query had been posted i.e. with this close a fit (1 cm) difference. I did not find any. Hence my post.

Thanks to let me know.

The sizing chats provided by manufacturers are only really a guide. One should never pick a size based on them alone.

The only way to select a correctly sized frame is to test ride bikes of different frame sizes. As mentioned in comments, body proportions make a big difference.

Don't approach a possibly too-large discounted bike with the mindset of 'can I make this work?' Get the bike that is right in the first place. There will be other deals that come along. Also, remember that with a used bike you'll be doing maintenance and replacing wear items such as the chain and cassette sooner than with a new one.


GRX crank with Ultegra groupset I currently ride a full Ultegra di2 setup with 50/34 chainrings and 11/32 11sp rear cassette.  I would like to run the GRX 46/30 chainrings because 50/11 gearing is a waste for me.  I could either stay with the 11/32 and get a lower gear or move to 11/28 and get tighter spacing.  Both my crank and the GRX are Hollowtech II, but I note the chainline on GRX is 46.9 mm while the chainline on my FC-R8000 is 43.5.  Is the chainline set by the crank or the bottom bracket?  If it is set by the crank, it this enough to matter?  Will a GRX crank work on the bottom bracket I have?

It's set by the crank, and is like this because GRX is targeted at 135mm/142mm rear ends. GRX takes the same BB as any HT2 road crank.

It's enough to matter, but chainstay length is the other piece of how much it matters. Doing this kind of thing on super short chainstay bikes can yield pretty compromised results in terms of number of rough combinations, and at the other extreme may not be such a big deal.


Old Kalkoff cross bike, worth restoring or not? I just acquired a used 21 gear old Kalkoff cross bike (cant even find correct model name). The frame and most expensive parts seem intact, so I was just wondering if it would be cool and inexpensive to restore bike: repaint, change faulty/old parts.

Community, help me identify how much would it cost to restore its functionality and aesthetic look. Which parts would you recommend and so on...

Here are the bike pictures: http://imgur.com/a/aqTHh

Big thanks in advance.

That isn't a cross bike. First, make sure the bike fits you. If it doesn't, its not really worth restoring (give it to someone who could use it). It looks to be spec'd with relatively cheap stuff, so I wouldn't sink a lot of money into it.

The first thing to check is if the frame has any major cracks or damage. If that is in good condition, check the headset to make sure its working smoothly, that the fork is functional (it probably doesn't work well, but if it bottoms out automatically its relatively useless), the pedals turn smoothly, tires hold air, wheels are true, brakes work (probably will need new pads), shifters work, chain is OK, derailleur not bent. A lot of this will likely require elbow grease and real grease/oil rather than new parts.

If the fork is in bad shape, you can likely pick up a rigid fork for not much money, but you need some tools to install it which probably means a trip to the bike shop or local co-op. If you take it to a bike shop and ask the guy to give it a safety check, he should be able to quickly determine what needs to be replaced for a few bucks. As for aesthetics, well, not much you can do there.

In all likelihood though, all you're going to need to do is oil the chain, adjust the brakes , adjust the derailleurs, throw on some new brake pads, adjust the cables (some may be broken and need replacement), pump up the tires, adjust the seat and handle bars and you're going to be riding off.


Tube patches: dedicated ones or recycling old tubes? Before I discovered puncture less tires, I had often to patch my inner tubes.

I initially bought dedicated patches (which invariantly were too big or too stiff), then decided to try cutting old tubes to shape, and using them as patches after washing away the white powder they had on the inside and giving both the tube and the patch a light scratching with sandpaper.

I find reused tube to be more easily workable, while being thinner and more similar to the tube they are going to patch.

Is any of the two to be preferred?

Recycling tubes as patches works, but its a lot more work and can be error prone.

You cut an oversized piece of tube and dust off all the talc.   Then stick a loop of tape on the back side as a handhold for later.   Then sand/abrade it really well, in three directions.

Once that's done you spread some proper vulcanising fluid on the sanded area so its got thin but complete coverage in the middle.  Then leave it untouched for 5 minutes while you do the punctured tube prep, the same way.

While the tube is drying, use sharp scissors to trim your patch to the ight size.  Use the tape handhold and do NOT touch the sticky side.  You can try cutting curves but I find a 45 degree corner snip then to much thinner snips off those corners works well enough.

Then if you can, inflate the tube to about where it would be inside the tyre, so abut 50mm for a MTB 2" tyre.  Stick the patch on centered over the hole.  There should be no part between them that doesn't have dried vulcanising fluid.

Lastly, use a roller, or a dollar coin or something round like the end of a spoon to press the patch firmly into the tube.

Peel off the tape handle, inflate to "firm" which is 5-10 PSI when bare, and leave for a couple hours to test.  If it holds pressure that long its fine.

Then roll and stow it, or refit to the wheel.

Upside - Recycling!  Save the planet!

Downsides

No chamfered edge to the patch, so any movement can wear a fresh hole.  Hence why it has to be stuck down all over.
Prep time is doubled.
Old donor tubes make for worse patches if they're already a bit ratty.

I once fixed a 20mm gash this way, cos I was broke.  That tube punctured again elsewhere but my bodge held for years.  I think its still in a spare 26" wheel hanging on the wall...


Please identify this vintage bike - peculiar frame Helping out a friend to identify this bike, it's got quite an interesting frame and is located northern nsw, Australia. Haven't been able to see a name or printing on it. It has 3 blue stars down the front under the Handle bars. If anyone knows or has seen a bike like this, am keen to work out it origins. Thanks

The three stars are the logo for "Malvern Star" which is an Australian brand that has been operating since 1902.

https://en.wikipedia.org/wiki/Malvern_Star

http://www.malvernstar.com.au/


Upgrading mountain bike crankset because worn teeth & chain slippage Every time i would google a bike issue this forum always come up so i thought i would join as it seems this group is very patient with beginners to the MTB world. I know there is similar post to this already on the forum but as i'm a complete novice & would absolutely love to be able to do my own bicycle maintenance, i really need exact help with what i'm trying to do.
I have TREK marlin 5 2019 mountain bike.
Which i now mainly use as a commuter bike & to take my child to nursery with bike seat and rack on the back. I haven't changed to road bike, as i ride along canal footpaths & cobbled streets & down flights of steps on the way back. I'm now getting very bad chain slippage when in the middle and biggest ring on the crankset. On closer inspection it looks some of the teeth have worn down (please see image new vs mine) which is crazy seeing the bike is only two years old. But its had poor maintenance and maybe with the weight of my child on the back this has happened sooner than it should.
To cut to point of my questions. I would like to replace/upgrade the crankset (as the current crankset is riveted together so i can't replace separate rings) also i would like to be able to go faster along the street. It currently has a "Shimano Tourney TY301, 42/34/24" can you please recommend another crankset that would fit this bike that has a bigger top chain ring to help with speed?
It looks like i might have to buy a cotterless crank tool & torque wrench to do this job?
I've always wanted to have a bike with Shimano Deore xt components ( but i know this would be super expensive for a XT triple crank set ) Could you please tell me if a Shimano Deore xt crankset would fit and what model number should i look for? If the XT components wouldn't fit could please recommend another shimano crankset that's bigger (in terms of a larger top chain ring) and would fit?
Could you also please tell me if i need to stick with a triple crankset (i would like the lowest gear still as sometime i do find some steeper hills)?
And by changing the crankset to bigger triple can i still use my current front and back derailleur's, cassette & shifters?
I have listed out all the current components out below.
Also would you buy a new chain a the same time?
Finally, if buying these two items doesn't solve the slipping issue, i'm guessing there could be a few things causing this issue, like a rear hub, or needing to change the derailleur's? If you could please try and help me diagnose what it could be, i would be hugely appreciative.
Sorry there are so many questions in this one post.
Really hope someone can take help me.
Shifters: Shimano Altus M310, 7 speed
Front & Rear derailleur: Shimano Tourney TY300
Crank: Shimano Tourney TY301, 42/34/24
Max chainring size: 1x: 32T, 3x: 42T
Bottom Bracket: Sealed cartridge, 73mm
Cassette: Shimano HGG200, 12-32, 7 speed
Chain: KMC Z51

It's quite unlikely you can't get enough top speed on that bike with those gears.
A 42/12 ratio with 29x2.2" tyres results in a 28mph top speed at 90rpm (most people could pedal faster). Since it is a mountain bike, you probably won't be going that fast except maybe down a steep hill, in which case not pedalling usually works out faster. On a lightweight road bike in a peloton this gearing might be insufficient. But for solo riding on an upright bike realistically you won't be pedalling very fast for very long because the air resistance will slow you down too much.
Your current chainset is non-replacable chainrings, so it's a fairly wasteful piece of design in that you must throw it away when you wear out a chainring. However since 7 or 8-speed (anything more requires a narrower chain and a total replacement of your entire drivetrain) is old, Shimano don't make a quality 8-speed chainset any more. So you might as well just replace with the same chainset you have now. It's heavy and disposable, but it works fine.
The other problem with your bike is the fork, which is a low quality one. Probably SR Suntour XCE or XCT. Upgrading this would definitely be more expensive than finding a used bike with slightly higher quality parts fitted (i.e. SR Suntour XCR coil at a minimum, but probably better an air fork).
At this point you can also consider whether you are not better off with no suspension, as this will make you faster and lighter work, typically.
Also there isn't anything specific to 'XT' as opposed to lower chainsets. Sometimes it means 'hollow crank arms', but sometimes you get that on 'SLX' as well. Usually the chainrings are lighter, but not necessarily more durable.
The advantages of XT are mostly in the shifters, which have 'instant release' and other features making them nicer to use, and in the rear derailleur which tends to be better quality.
You could definitely upgrade your bike to something more like the Marlin 7
https://www.trekbikes.com/us/en_US/bikes/mountain-bikes/cross-country-mountain-bikes/marlin/marlin-7/p/33148/?colorCode=orangelight_red
but this would need:

new shifters (XT are the best choice)
new rear derailleur (XT is the best choice)
new front derailleur (Deore is fine)

on top of what you already need which is:

crankset
probably new BB
cassette
chain

And these parts would be more expensive ones as well.
Doing that is fine, the problem is having XT parts and that awful fork is kinda not a good match.
So you're likely better off looking for a used 3x10 speed bike if you wanted to go that route - it would have better parts all around.
BTW I'd recommend the X8 chain for higher durability rather than the lower Z series you have.


Disc brake pads are loose in the calipers, is this a problem? I recently bought a new commuting bike (Norco ccx3) which has mechanical disc brakes (Promax DSK-715 Road Mechanical Disc). Thus far I've been pretty happy with them.

In the last couple of commutes, I've noticed an ocasionally 'ting' sound coming from somewhere on the bike when I would hit a bump. This morning I figured out what it was.

On the front brake, the pads are a a bit loose in the calipers. That is, the spring clip thing is still in there, but when there is no pressure on the brake cable, the pads can rattle a bit between the caliper and the rotor. With the wheel in, there doesn't appear to be enough room for the pads to slip out and there still is a fair bit of pad left.

Is this normal, or is there any danger to this?

"ting" sounds with mechanical calipers are not uncommon. The rotor flexes when steering and the pads do move a bit. Some calipers use magnets to hold the pads in, some use springs. I wouldn't be too concerned.


Is it possible to replace a 1 1/8 steering tube with a 1"? I have a 94 Giant ATX. Threaded 1 inch steeering tube.

I need a shorter stem, and would also like to install a suspension fork.

Is it doable? Could I take a modern suspension fork, heat the crown, smash the steering tube out, install a 1" tube (with some added metal so that the outer diameter is 1" 1/8) the get rid of the threaded headset and install a threadless 1" headset (does it even exist?)

Bear in mind that I'm in Argentina, and it's very difficult to get parts from US shops.

I'm going to recommend that you NOT do this.

There were in the past manufacturers of 1" steerer suspension forks - though I'm not certain that they're are still sold. It is important to note that bicycle frames built to accept solid steel forks have different geometry than those built for suspension forks. The frame is designed for a fork that doesn't have suspension travel - the head tube is taller, the down tube and top tube are welded to preserve the set geometry of the bike. Installing a suspension fork would lift the front of the frame up and slacken the head tube angles - overall, I suppose it isn't a huge deal...HOWEVER...

If you're having a hard time finding bike parts, will finding a 1" steerer tube, a suspension fork that has a brazed steerer tube, a bushing that is machined to fit precisely and a machinist to make your bushing, and someone to braze this all together be any easier than finding a more modern bike frame or a used 1" suspension fork?

You might be able to remove the steerer from the suspension fork if it is brazed in, but retrofitting a new steerer tube will require a bushing machined to VERY precise tolerances to allow for heat expansion and brazing filler flow. Any valves, adjusters, stanchion caps...anything not brazed or welded to the fork crown will have to be removed to prevent any damage while heating. You'll want this done professionally because a failure while riding would be regrettable.

With the amount of work involved, it may be more cost effective to track down a mountain bike frame with a 1-1/8" suspension-ready head tube or just have someone replace the head tube in your existing frame.

Also, it may not be too difficult to find an affordable bicycle in Argentina. Here is the distributor for Giant bikes in Argentina. You can email them at: info@giant-bicycles.com.ar. You can locate Giant vendors by province here. If Giant is represented there, you'll likely find other companies and reputable bike shops who can order you frames, parts, bikes, you name it.

Added info:

Here is a forum thread detailing fork building. The most important point is the fit of the steerer to the crown. If it is too tight, the brazing filler won't flow evenly and consistently, too loose and the integrity of the braze is compromised. If you do decide to do this, definitely try it more than once. The first two or three you should cut up to inspect the brazing filler flow (cut lengthwise and try to pull the pieces apart. Bubbles, seams, and burnt flux are all signs of a poor joint.) There is a comment about brake bolts and wedges being used to prevent steerers from pulling out of the crown, but I wouldn't risk it.


increase highest upper ratio with gear hub I have a 20" folding bike with a shimano Nexus Inter-3 (most probably this one), and I find that even on flat terrain (not to mention downhill) the 3rd gear is simply too slow: I often find myself cranking very fast exerting a very low torque, and 2nd gear is good for most slopes (<15%). I mainly use the bike for commuting, on mostly flat terrain.

My current top speed seems to be around 20-25 km/h, I would like to be able to do 40 km/h. That means an increase by a factor of two.

I am searching for a way to up the gear ratio, my options seem to be:

Increase the size of the front chainring (45 currently):

This would make folding harder.
I would also need to change the chain protector and possibly the pedals.

Decrease the size of the rear cog (18 currently):

This would increase the strain on the individual cogs and increase the chance of slipping (that already happened) and chain fall-off.

Change the gear hub to one with a higher upper ratio:

May need to change the shifter and corresponding wiring
May not fit in the current frame
The current ratio is 1.360, I would like at least 1.8 or even 2.0
I do not really need gears below 1.0, and certainly not below 0.73 (my current 1st gear). Unfortunately most gear hubs concentrate on the lower gear ratios, but I am yet to find a comprehensive table of available gear hubs (wikipedia's, and Sheldon Brown's have different flaws). Shimano's 4-speed hub seems promising, but is discontinued.

Which solution (or combination of them) do you recommend? If it is the third, what specific gear hub(s) do you recommend?

Decreasing the rear cog is by far the easiest of your options.  On road bikes, chain rings of 34-39 teeth and rear cogs of 11 are common, so you would be within range. The force on the chain is higher for smaller chain rings, not larger ones.  Slipping probably comes from not having the chain tight enough.  You may be able to move the rear axle aft to tighten it.


What sort of bottom bracket does a Trek 1.5 2011 take? My bottom bracket is on its way out.. No longer getting smooth rotation even without chain attached. I was wondering if anyone knew what sort of bottom bracket the frame supports? I've googled but the results are fairly mixed.

Also I assume I just need a special bottom bracket wrench to replace it, is that correct?

Cheers,
John

From Trek's archives and Bikepedia, it looks like that bike has an FSA Vero compact crankset (no mention of the bottom bracket (BB)).

From the Amazon page for the FSA Vero Compact it appears the crank is compatible with a JIS square taper bottom bracket.

JIS square taper bottom bracket is a common type of cotterless bottom bracket, available from many manufacturers.

You'll need to check that the bottom bracket shell sizing and threading matches the BB, too.

You will need a special tool to get the crank off and another for the BB.

See also:

Sheldon Brown on Cotterless Crank removal
John Allen on Cartridge BBs
Park Tool on Cartridge BB servicing
Park Tool on BB tool selection
Park Tool on Cranks


Disc brake pad replacement, or replace whole caliper? We have a Boss Stealth 26" men's mountain bike with Zoom brand disc brakes.

The disc brake pads are worn and need replacing, the problem is finding a workshop who can fit them as apparently it is a budget bike and hard to get the brake pads.   Is it possible to fit another make of caliper which are readily available on ebay?

Both front and rear rotors are 160mm, or are the sizes from disc to frame bracket different?

If you cannot find replacement pads, many cheap off brand disk brakes use BB3 pads, have a look and see if they are the same. Changing the yourself is straight forward enough. Sometimes its as cheap and easier to replace the caliper, especially if paying a mechanic to source hard to find replacement pads. If you do, get one that is major brand, or at least takes major brand pads.

If you want to do it yourself and cannot find pads, there are two mountings for calipers, IS and Post. Generally buying same style caliper as you already have makes it a simple replacement. Adapters will probably cost more than a cheap caliper.

Disks come in two mounting standards as well. 6 bolt and center lock. If you want to replace the disk you will need the get the same type.


Rear derailleur shifting from 1st to 7/8th with one click I have recently replaced shifter cable and reset the pulleys so that they are in line with the cogs.  I've set the high and low limits and have the gears shifting nicely upward & have fine tuned with the barrel adjuster.  When shifting back down the gears just jump from 1st almost straight down to 7 & 8th cog after only just one click of the shifter!!

Help....any recommendations on how to fix please?  Cheers

My first thought is you need to clean your shifter. There is a ratcheting mechanism in there which is the thing that makes the distinct clicks when you shift. When the grease is old the little pawl (the thing that locks into the teeth of the ratchet wheel)  will sometimes not want to rotate properly which can cause your shifter to skip gears.
Removing the shifter cover, spraying it with plenty of wd-40 or a similar product and shifting up and down a bunch of times should solve the problem in most cases. If that doesn't help you might have to clean it a bit better using for example cotton buds and a solvent or cotton buds sprayed with wd-40.

This phenomenon is called a 'sticky shifter' iirc. Here is a video on how to possibly solve it:

(Note: the issue shown in the video is not your exact issue but the video does show how the ratcheting mechanism works and following the steps in the video should probably solve your issue as well


Does ProPedal on FOX RP2 rear shock wear out when on during downhill? Yesterday I forgot to turn off ProPadal before quite nasty downhill ride on my Fox RP2 rear shock (riding Giant Reign 2011) - I can imagine this makes no real harm to the shock but think there can be some extra wear of rubber sealing etc? The downhill was about 1km of a very old road paved with big round sandstone rocks (about 0.5 m in diameter), I think I could have used about 75% on my suspension travel, the shock could had bumped about 300-500 times.

While shocks are certainly meant to be locked out and ridden, even over semi-rough terrain, there are probably some limits to the design. I'm not a fork/shock mechanic, but what I know about fluid dynamics tells me that you shouldn't do this too often!

When you lock out your fork/shock it limits that compression of the fluids inside or prevents compression at all by preventing other parts from moving.

Scenario 1: The fluid isn't allowed to move through the damper. You could cause high pressure build up on a seal or damper and cause it to blow, or even rupture the canister.

Scenario 2: The parts are prevented from moving. The forces exerted on the locked parts could be more than they were designed for and could cause premature wear to the point of failure.

Again, I'm not a professional, but I wouldn't recommend riding like this regularly. Perhaps a quick email to Fox might be more helpful, as they may have actually done testing to see what happens when a rider rides the rough stuff with a locked-out shock.


Is a chin strap with a cup safer than an under-chin strap? Many helmets have chin straps to hold them on.
One design uses a split chin-strap, where the strap splits into two forming a cup shape, one going just below the lower lip and one under the chin.

In my opinion, this is a more comfortable design as the chin strap is against the chin bone instead of pressing against the fleshy underside of the lower jaw.

I found a single link http://www.usyouthsports.org/images/CPSC_Hangman_s_4_point_chin_strap.pdf which claims that this design is safer for bike helmets as it may reduce some cases of strangulation in case a "yanking" force is applied to the helmet.

Were there any other studies done on chin strap design like this for bike helmets?
Is this design safer?
Are there any bike helmets actually available with this chin strap ?

Helmet strap will strangle kids, there are cases of children in play grounds not being able to get out.
I would add the magnetic buckle as the solution to these problems. e.g.
https://www.fidlock.com/en/helmet-buckles


Is there a standard disc brake mount to disc brake rotor distance? I'm new to disc brakes and trying to figure out what I need to buy to buy them for a wide fork (135 mm dropout spacing) with IS disc brake mounts and an electric front wheel.  I've researched, but I haven't found any information that specifies a standard distance between the I.S. front disc brake mount (i.e. where the disc brake caliper attaches to the fork of the bike) and the disc brake rotor.

Given that getting this distance correct is crucial, since a few millimeters distance is all it takes for the rotor to rub up against the caliper pads, I would think there would be a clear standard distance, but I haven't found one.

The standards for disc mounting specifies a distance between the rotor and the inner face of the dropout. This distance is different for front and rear brakes.

A 135mm spaced fork sounds like a fatbike fork. Early fatbikes used 135mm front and rear, often specified to allow two "rear" wheels to be used, and swapped in case of freewheel failure or to change singlespeed ratios. Hence, some fatbike front hubs are labelled "RDS", meaning rear disc spacing.

Nowadays, fatbikes with 4" rear tyres tend to use 170mm QR hubs or 177mm thruaxle hubs, and 5" tyres usually have 190mm QR or 197mm TA hubs. The front hub will generally be 135mm QR or 150mm TA, but both would normally be spaced like a normal front hub.

I think front spacing requires the caliper to be mounted 4mm wider than rear spacing, I'll try to find a spec document later.


How long does a freewheel cog last? 4 months I asked this question when I changed my chain:
What can be done wrong changing the chain in a single speed? and the solution was to change the freewheel cog.

I decided to "invest" in the not cheapest model. I just found two possibilities the halo clickster for around 50€ and the white industries for around 120€, or the same I had some kind of no brand for 20€.

I decided to get the mid range halo clickster. Well after just 3 months and around 3000km I decided as maintenance that it was time to change the chain. So I put the new chain and I get the same kind of noise.

Is it normal that it is already worn out? Does it make sense to pay more for just a little amount of km?

This is how it looks:

And this is how it sounds, just when I give it some power.
https://streamable.com/hfqlp
The tension from the chain is not high, i can move it in both directions at least 2cm.

3000km is enough of a wear life for a singlespeed freewheel that I would say there's nothing necessarily wrong here.

One way to check wear is just looking at the side of the freewheel teeth that contacts the chain versus the side that doesn't. The more asymmetry, the more wear.

If you ride it like it is, it probably will break in and get quieter, but what's happening there is your chain's pitch elongating to "catch up" to the freewheel, which isn't necessarily a good thing.

I don't have experience with the Halo one but it sounds like it might be a little too boutiquey for its own good. The cheaper Shimano freewheels are pretty excellent at reliability, wear life, and not being too painful to replace when they do wear out.


What is the full name of this bicycle? Thank you! Can anyone help me find the full name of this bike? i would really appreciate your help. Thank you!

That looks like a Cervélo RS (from some time around 2008) with an aftermarket Easton EC90 fork and DT Swiss wheelset fitted.

You can find a review of the bike from when it was released here.


Shimano Hydraulic brake 90-degree angle hack Does anybody know of a way to get Shimano Hydraulic brake hoses to exit the levers at a 90-degree angle?

I ride a recumbent and at the moment I have to put up with a huge loop in front of my eyeline to get them down the steerer. If it came out at 90 degrees, it would clip direct to the steerer, look neater and probably be a bit more aerodynamic.

Could I just fit the same connection as is used to enter the calipers?

If you are willing to switch to a Zee, or Saint, brake the hose is connected at the caliper via a banjo-style connector, which allows for usually about 270deg. of motion around the axis of the fixing bolt. Many brakes use this kind of connector, but on Saint and Zee models, the fixing bolt is parallel to the caliper mounting bolts and pads, allowing the hose to be positioned at a 90deg. angle from the caliper, as seen from above. I'm not sure which direction you want the hose to point, but other brakes have the fixing bolt in other orientations. SLX and XT have it perpendicular to the previously mentioned models, so the hose pivots parallel to the pads. Tektro/TRP, Sram, Formula, and Hope all make brakes with banjo fittings. Check photos of the calipers, there's definitely something out there that cant point the direction you want!


upgrading components on replacement? Is it practical (or is there any reason not to) upgrade components on a bicycle when they are replaced?  For instance, I've got a 10 speed cassette on a tour bike that needs to be replaced.  The bike is mostly Tiagra components, but is there any reason (other than cost, but in this case it seems like it's only about a $35 difference) to not upgrade to 105 or Ultegra?  (Staying within the same 10 speed part.) Are there certain components that have to be replaced as a set if I upgrade?

I have looked at this compatibility chart, and if I understand it, it is saying that an Ultegra ST-6700 is a drop-in replacement for a Tiagra ST-4600.  But I'm not sure if that is everything I have to look at, can I just do a drop in replacement of any component in any box?

I'm also concerned about whether there could be other issues with mis-matched components, for instance will a better component in one place lose some of its benefits or be degraded by a lower grade component that it interacts with?

There's no harm in doing so, as long as you identify compatible components.

You do take a hit on cost, by which I mean that components work out a lot cheaper when bought as part of the bike, rather than standalone. So economically it would probably make sense to stuff the money in a piggy bank, and save up for a new bike with better components, since when that time comes you'll get more bang for your buck. But if your pocket is willing to take that hit, go for it.

I haven't looked at your specific case but in general, upgrading from something Shimano to something Shimano will work, as long as both mechs have the same number of gears on the cassette. 6700, for example, is a 10-speed system so as long as 4600 is also 10-speed, you should be safe.

The other caveat to bear in mind (when upgrading brakes/shifters) is that a couple of Shimano mechs have different pull ratios to others. In fact, there was a question about this just a couple of days ago which I remember links to a document explaining what mechs are affected.

Lastly, while I start by saying there's no harm, there might also be no gain either. That's going to depend on you, and on the rest of the bike. So you're right to raise this in your question, but it will result in "no gain" rather than "harm".


Armadillo's or Kevlar Inserts? So, I've had at least two flat tires on my way to work. Therefore, I'm tempted to splurge on  a pair of Specialized Armadillo's (not the elites...)

However, I am not a particularly skilled rider.  I had a pair of racing slicks from the late 1990's (at the latest!) and they were a tad on the nightmarish side - I slid out at 5 miles an hour trying to leave a parking lot.

Seriously - slicks were enough to give me an existential crisis.

At the same time, I'm notorious for being, err, close, yea, that's it.  Close to late.  As such, I don't really like flat tires.  My choices at the bike shop came down to this: cheap gumwall tire with treads and Kevlar Inserts, or a pair of Armidillo's which have minimal treads.

Which should I choose? I commute in all weather conditions.

Speed is nice, but I really care more about not dying and not calling in late from the side of the road than minimizing rolling resistance.

Your sliding out at 5mph wasn't because the tires were slicks, it was for some other reason. They were either lousy tires, improperly installed, rider error, or some other factor.

If you are riding on the road, there is no need for any kind of tread. Slicks are perfectly fine, despite your thoughts from your previous experience. In fact, they are ideal, and will be easier to handle on the road than tires with tread. A definitely don't get any of those combination tread tires, those are the worst.

Forget the treaded tires with kevlar inserts. Get the Armadillos, Continental Gatorskins, or some other sort of flat resistant tire. Make sure they are always pumped up before you ride, and they'll serve you well.


Is the Shimano SL-M590 shifter compatible with XTR RD-M900 rear derailleur? Shimano is known for making their high end components incompatible with their lower ranges (e.g. dura-ace 7400). How do they handle this on their mountain bike range? In my case, I'd like to run a RD-M900 or RD-M910 with a pair of SL-M590 shifters in a 9 speed configuration. Will there be any issues?

Your information is a little out of date, but for 9-speed, all road and mountain rear derailleurs and shifters are cross compatible from xtr and da to Alivio and Sora.
Other combinations work to but for the purposes of your question, there are no issues or likely problems from your component selection.


1/3 Century or Metric Century? Should I choose the 1/3 Century or Metric Century for my first organized, supported group ride?
In one week I will participate in my first organized ride since buying my road bike in May. The longest training I've done is 28 mi averaging 14-15 miles/hour on chip sealed roads with maximum elevation gain of 800 feet. Both routes will be similar terrain and elevation change.

You're asking should you try to ride 33 miles or 65 miles when your longest training ride is shorter than either?

I think you'd be much better off trying a 60 mile training ride before the event. Sure, you could probably do that on the day, but you could easily end up either failing or struggling through and feeling miserable.

If you think the "supported" part will make a difference perhaps try carrying a bit of cash and choosing a ride that lets you stop a couple of times at shops where you can buy snacks and drinks. Personally, I'd carry both on the ride. A extra couple of pounds isn't going to make any difference unless you're right on the line before complete exhaustion stops you. And you shouldn't be there.


Front wheel compatibility I have a pretty cheap bike (29" Genesis Two-Nine) which served me very well for 2 years and now the front wheel got stolen.

Are front wheels universally replaceable and if yes, what are properties which must be equal? For example, my bike had a 29" mountain bike front wheel with a disk brake. Will any wheel with these properties match the bike?

There are 3 things to worry about and you've covered two.

Size, the wheel rim should match the current size.
Brake compatibility, if you have disc brakes you need a compatible hub, could be 6 bolt or centerlock. It has to be compatible with the rotor you will also purchase. If you have rim brakes you would purchase a rim brake compatible rim. (you can use a disc hub on a rim brake).
Axle compatibility, there are current at 4 main axle widths and lengths 9x100mm QR, 15x100mm thru axle QR, 20x110 thru axle and now 15x110 thru axle. You need to select the hub that is compatible with your fork. A 15x100mm wheel can work on a 9x100mm fork with the use of a shim.


Using a wider inner tube I am switching from 700cx40 to 700cx32. I have a bunch of inner tubes that I bought for the old tires and are in the 40mm range, but I don't know anymore what the range is for each (I didn't keep the packages). Is there a way to tell? Or, if no, what can happen if I use a wider tube (say, a 35-xx or 37-xx tube on a 32mm tire)?

EDIT: OK, I see, the dimension is written on the tube. So, I have a 700 x35/43 tube. Is it safe to use it on 32?

Yes, it's perfectly safe to use the next larger size tube in a smaller tire. It's a common trick used by bike messengers to reduce the chance of flats. The only downside is a slightly heavier wheel since you're using more tube that you really need.


Need easier gearing. What would the effect of changing the chainring or cassette be? My mountain bike is too difficult to pedal when the going gets steep.  I need an easier gear ratio.  Am I better off switching the chainring or the cassette?

I currently have:

A 30 tooth FSA chainring.  A 28 tooth ring is available that would fit my crankset.  See other question.
A Shimano 10 Speed 11-36 Tooth Cassette.  I haven't figured out the compatibility yet, but Sunrace makes several 11-42 cassettes.  They are around ~$80 (CAD) but may require special derailer hangers.

What would be the effect of choosing either of these options?

10 speed with a 42 really needs a Rad-Cage or Wolftooth Goatlink. It's a dogs breakfast, starts out smelling dodgy, and ends up smelling even worse. Some have succeeded, but many have found the conversions finicky and less than ideal. It had its day when the only 1x was XTR or equivalent, and people accepted Acera performance from 'upgraded' XT. Not sure if those third party bits fit the Deore deraileur you have though.  You could try an 42 with the Deore, but you can run into problems with lack of chain wrap and getting onto the 42 tooth cog - if it works, expect pretty crappy shifting onto the top cog.

This leaves the 28 chain ring - a good option if you don't mind loosing a bit of top end speed. Its cheap and easy to install, but only gives a little advantage over 30.

IMHO The best option by far, is upgrade to an 1x11. You need is a cassette, derailleur and shiftier and chain, so not cheap. It gives you option of a 46 cassette, and will work properly. If you cannot afford this, go for the 28 chain ring, keep the 30 tooth and save for a 1x11.


Correct way to shift? So I went to a bike shop to check out the options that I could buy and came across this board that has the gear using system explained for beginners (I guess?).

Is it not literally suggesting cross-chaining? The bike I'd most likely buy will have Shimano tourney derailleurs, both front and back.. Is this the best way to go about using the setup? The setup is a 3×7 and would be used mostly on flat roads. I'm also thinking about removing two of the chainrings since only one chainring makes more sense. (probably keeping only the middle). Say, I make it a 1x setup after removing two chainrings, (keeping just the middle one), will I still meet with cross chaining?
Yes, I've looked at options that have a 1x setup, but they aren't very reliable, and most of them have cheap suspensions and cheap disc brakes on them, both of which I want to avoid.

Is it not literally suggesting cross-chaining?

Cross-chaining is putting a chain at extreme angle between front and rear cogs. The picture above illustrates correct ways to use the front triple. Incorrect ways would be: the biggest front ring with the biggest rear one, and the smallest front one with the smallest rear one.

I'm also thinking about removing two of the chainrings since only one chainring makes more sense.

I've seen/used the Tourney group and agree that the ratio range it provides is unnecessarily big for flat road applications. However, removing all but one front chainring, in my opinion, will leave you with a very narrow range at the back. Most people will be comfortable with existing two front chainrings of the Tourney setup (the smallest and the middle one), as the biggest front cog only makes sense for quite steep descents and high speeds, unusual for leisure cycling (or at least for non-mountainous terrain).
Note that chainrings on Tourney are riveted not screwed to the spider, so removing them will require some drilling or smashing. Putting them back on will become problematic as well. That is why I do not recommend it.

Say, I make it a 1x setup after removing two chainrings, (keeping just the middle one), will I still meet with cross chaining?

Strictly speaking, yes. The 7-speed chains were not designed to bend through the whole range of the rear cassette. Having a middle front cog with either the biggest or the smallest rear cog will constitute cross-chaining, albeit less grave. It will most likely work, just that it will not be in the intended use/range of the setup, and might lead to decrease in chain/drivetrain life, decrease in shifting reliability, may produce additional noise etc.
On top of that, you may start experiencing chain drops if you remove the front derailleur cage, serving as a chain catcher. True 1× setups have additional measures to increase chain retention, which Tourney does not provide. Again, in the Tourney case, the gearing range will just be very limited.


Should my aftermarket frame have a serial number on it? I was riding a mostly custom WTP Crysis frame which had a serial in case the bike was lost or stolen. I snapped the drop out arms on Sunday and ended up buying a new FBM Hard Way frame. I checked all over and haven't seen the serial numbers. Part of me thinks there should definitely be one, but I'm not sure where to look.

Does FBM allow me to register it online? I don't want to be at the point where the only evidence of it being my bike is "I have this pic of it in my apartment" and a bike shop receipt. But my bike shop receipt only says "BMX 20.75" frame" and doesn't say make, model or even color.

I would be surprised if any quality frame does not have a serial number. Many manufacturers warn against frames with no number, or numbers scratched off, so your concern is somewhat valid and you should follow up on it. Also reading http://fbmbmx.com/products/frames/fbm_warranty.php suggests the frame should have come with a warranty card.

Photograph the frame with the receipt and send it to them, specifically expressing your concerns. They will confirm fairly quickly if its genuine.


Thru axle on unthreaded cyclo cross frame I have recently purchased a cyclocross frame to take front M15*100 and rear M12*142 thru axles. The frame has no thread in front fork and rear for the thru axles. What axles do I need to purchase and where are they obtainable?

This strongly suggests that the frame and fork have removable/replaceable threaded bits. There aren't really standards for these; they're more considered part of or specific to individual frames/bikes. It's the kind of thing you tend to have to get from a dealer for that brand or in some cases direct from the manufacturer. If this is the case, once you have them you would be able to measure the effective dropout thickness on each side and from there you'd be able to add those numbers to the spacing, and then you just buy a thru-axle that long with the right thread. Or you could just get them from whoever you get the frame fittings from.

There are some thru-axles that are unthreaded. Suntour Q-Loc is the main one running around currently that I've seen, but it's pretty common. However, it's only on suspension forks that I know of, and not on road/cx bikes at all, so I doubt it's what you have. But if the frame and fork feature a long, plain bore where something might fit through and don't look like they're missing anything, it's possible it's something like this that you need.


Change gear on a shimano Schwinn Ranger, not sure what Allen key size to use? I've tried an Allen key 7/64 but that didn't work and the others on my Allen key set but none seem to fit this shimano on a Schwinn Ranger.

One of the derailleur cogs broke in half.

Here is an image of a similar bike with the same Shimano drive train.

http://www.target.com/p/schwinn-mens-ranger-26-mountain-bike-red/-/A-15287654

Thank you!

The allen is almost certainly metric.  Both 2.5mm and 3mm are reasonably close to 7/64 inch.  3mm is a very common size on bikes.  If you are going to do any work on a bike you need metric allen wrenches.


Proper tire pressure for my bike? I wanted to ask about proper tire pressure specifically for the bike I got.

The model is Oryx Volt 26".
Tires specs are: 26" / 2.125".
I believe Toronto Police used such bikes.
Recommended pressure written on tires is 40 - 65 PSI.
I drive mostly on roads and forestry parks. Don't have any mountains.
Weight 82 kg, 180 lb.

How should I inflate my tires?
To a recommended 60 PSI or so?
Should I inflate tires equally?

What confused me is that tire pressure articles I read on the web say that for mountain bikes tire pressure should be around 25 PSI.
But my tires have recommended pressure 40 - 60 PSI.

Thanks.

Your tyre suggests 40-65 PSI, so that's a good start.

The lower pressures are much more likely to pinch-flat as the rim bottoms out on the ground, if you're riding over a rock or lump or kerb/curb.

For your weight, on a MTB on the road I'd aim for 50-55 PSI, and vary it by a little to see if it feels better or worse.

Generally the rear wheel is holding about 60-70% of your whole weight, so it makes sense to add 5 PSI more in the rear.  Again, try and see how it feels for you.


About 20-30 people bike to where I work. What equipment/supplies should we have on hand? I work in San Francisco, and I'd estimate about 20-30 people bike to where I work. We mostly have a mix of road bikes and hybrids with a couple commuter bikes and mountain bikes too.  Currently, the only equipment in our bike cage is a locking entry door, a double-decker bike rack similar to this one, and a single floor pump.

I was thinking that we could start with some basic toolkit or repair kit, spare batteries for lights, loaner headlights and tail lights, and maybe a couple loaner helmets so people don't have an excuse to ride without helmets.

What else should we stock?  Are there premade kits for a situation like this?

I'd maybe ask the cyclists themselves - maybe ask them to bring useful spares and have an amount of petty cash on hand to reimburse them. They might be able to bring in old lights (let's face it many of us always leap to the newest kit and have drawers full of old kit lying around).

The basic tool set should include tyre levers, an adjustable spanner/wrench or combination bike tool, Allan keys (hex wrench).

If you're prepared to keep things topped up with consumables as well, that would be great - but you'll be forever replacing the inner tubes, but while you might need a mix of sizes, starting just with a few 700x25c would work.

I'm not convinced about spare helmets - apart from the whole obligated helmet wearing debate - you might be opening yourself up for liability if someone got badly injured in an accident while wearing one of the loaner items.

Many lights these days are rechargeable themselves, either through USB or directly to mains, so making sure that there are charging sockets and a charged USB hub could be good, maybe a battery charger would encourage people to switch to that style of battery.


Do I need to chase a thread before installing a bottom bracket on a new frame? Currently I'm building a new Surly Cross Check, and it needs a 68mm BB (english threaded).

Furthermore, I plan to use a cheap $15 shimano BB with JIS square tapered interface, nothing special.

Do I need to bring my frame to a LBS and ask them to chase the thread? or I can just use a toothbrush and some soap to clean the thread?

EDIT 1:

Is Chasing necessary? or is it an optional process to allow the BB fits better?

EDIT 2:

picture:

The ink splat is because there's a hole for dérailleur cable hanger.

If you don't chase when you need to, you'll have a very tough time threading the bottom bracket in, and as a result, it may creak or wear out somewhat faster than it would otherwise.

The same goes for facing the bottom bracket shell.

This is what I would do (and have done) if I were in your position, only for square taper, cartridge bottom brackets*: Since you are using a square taper bottom bracket, your BB will likely have one fixed and one free cup (or whatever its called). Take the free cup, and thread just that into the shell without using any tool besides the driver (example), only finger tightening it. If you can thread that all the way in until its outer flange is flush with the shell, then your frame is "good enough" as it is. Unthread the free cup, and install the BB properly and you should be good to go.

If you can't get the free cup all the way in without using tools, then I would have the threads chased out.

I used this method on my Surly Cross-check frame in 2007, and the threads were good enough then, and I haven't had any bottom bracket troubles whatsoever.

And cough up the extra cash to get the better bottom bracket, it will last longer, and every time you have to take square taper cranks off, you wear them out much quicker.

*Hollowtech and other outboard bearing systems are more sensitive to the threading, and especially the facing of the shell. If using those systems, always have the bottom bracket faced, and at that point you might as well chase out the threads.


Turbo training programs for long distance events Can anyone suggest good turbo trainer workouts (or tell me what features are necessary) for training for a long distance cycling event (Vätternrundan ~300 km)?

I need to be fit enough to cycle that distance but also need to get my raw pace up because of a tough target time (8 hours requiring about 40 km/h [in a group of 28 riders]) - what sort of drills should I be doing (or what should I avoid) to increase stamina and power efficiently?

Turbos are great for short interval work, brutal power workouts (cf. the comment above citing sufferfest.com) where you can monitor your output and heart rate more accurately. But they are dull, mind (and body) sappingly dull.

I'd save the long workouts for the road, it's more interesting and you've got mates to chat to and spend time with.

Use the turbo for working on the raw pace, short (60-90 minute) pieces with shorter, harder threshold pace intervals.


Rollerbrakes very noisy when used One of my bikes has "rollerbrakes" (commuter bike). When I brake very gently, they work silent. If I squeeze the brakes a liiitle more, I hear a terrible metal to metal screaching sound. It makes pedestrians jump out of the way, which is an undesired side effect (well, most of the time). Should I adjust them? grease them? replace them? ...

Roller Brakes (a form of drum brake) do need a regular service, which does require grease (yes it does seem weird to grease brakes) as there are some moving parts that can rub. You should be able to buy some Roller Brake grease/oil and apply to the appropriate location. I am not 100% familiar with Roller Brakes, so you may need to check the location in your manual, or perhaps someone else can help out with the description of rubber cover if needed.


Adjustable stem busted - Do I need to replace the whole stem? Today on my 2018 Pegasus Solero the adjustable stem broke. Probably due to overtightening of the righthand screw the nut at the left side of the stem tore free (see images).

The question is, whether I need to replace the whole stem or if there's a chance to buy only the nut somewhere. Also, how can I prevent this from happening again?

I'd call that part garbage, sorry.  You've overtightened it enough to tear apart the metal, and that toothed flange is probably custom.

I would suggest replacing the whole unit with a different brand.  The one pictured APPEARS to be a threadless stem, but with the steerer clamp down below and the hinge/knuckle up on top somehow.  This is quite unusual.

Now that you know what kind of angle/length you prefer on your stem, consider purchasing one that fits those specs.

A conventional non-adjustable stem might look more like this:


What features should I look for in a cool helmet? I have a Bell Metro  helmet. It's fine but even with all the holes, it is very hot. It also causes skin irritation on my forehead and causes (sorry people) pimples on my scalp. Are there specific features that I should look for to have a cooler (as in temperature) and less irritation experience for my head, as it exists under the helmet?

The most important thing to look for when shopping for a helmet that will keep you cool is that air flows all the way through it from front to back.

Put the helmet on and look in the mirror. If you can see all the way through the back of the helmet, it'll probably keep you relatively cool. And the more you can see through it, the better.

Higher end helmets will also sometimes have vents that scoop air down into the helmet. The vents are raised at the front and lower at the back to force air down into the helmet as you ride along. I don't know what your budget is, but you'll probably pay a pretty penny for one of these.

You could also try wet bandana on your head. That works wonders for me.


Can anyone recommend a good maintenance-free rear shock? The old shock just gave up its life in my old single-pivot all-mountain frame. I'd like to replace it with something tough and maintenance-free, so that I don't have to worry about air pressure, oil leaks and other things to check before I ride. It should also be mud-proof as much as possible. Weight, price, performance and all others are secondary. Does anybody have a good recommendation? 160 or 165 mm length.

Also, is there more than one standard of mounting rear shocks? I vaguely remember some sort of ball joints being promoted for this a few years ago, but I don't know if this caught.

All shocks require a little bit of love from time to time. A coil rear shock will require less maintenance than an air shock. The simpler the shock, the less maintenance you will need to do. I have only ridden fox in the back, but have never had any issues. I would recommend looking at the Fox Van R Coil. The Rock Shox Vivid would also work really well.

If you want to be able to pedal well, you should look at the higher end coils that have propedal, or airshocks.


How to replace a bottle dynamo with batteries I have a bike using a bottle dynamo.
It works ok but I just use the light when it's absolutely needed because the dynamo really slows down the bike.

I would like to make the bike run with batteries, what is the easiest way?

I solved this by attaching a USB connector to the existing light circuit, and power everything with a cheap cellphone power bank.
You just need a USB (possibly broken) cable whose "computer" end is working, and a place to hold the power bank.

A saddle bag is a perfect place for it. The front basket can also do.
Make sure the USB plug doesn't get too much water, it may get rust. For example leave it inserted in the saddle bag.

Assuming you have basic technical knowledge of electronics, it's a very easy process.
You can attach the cable at the old location of the dynamo, or in parallel of one of the lights. Just keep in mind that usually on the bike the "ground" is the frame, and the "live" is the only cable. USB side, black is the minus and red is the plus.

Polarity doesn't matter with bulbs, but it may matter with some led lights. If it doesn't work, reverse the polarity.

LED lights are brighter and will last for much longer. There are very cheap  replacement LEDs using the bulb form factor.

The light could be a bit weaker due to running at 5 Volts instead of the usual 6 that you get from a bottle dynamo, but most of the time it will be much stronger as it doesn't change with speed.


What size is the upper bearing on a 2013 Trek Speed Concept 7.0? I'm looking to replace the upper head bearing in my 2013 Trek Speed Concept 7.0 but cannot find the item online. Any ideas of a FSA/Canecreek bearing to replace it?

Just to clarify, the diagram below shows the 2014 service manual that depicts an upper head bearing of W276442. I don't know if that's the same for the 2013.

I got the answer from Carl an Engineer at Trek. Turns out it is:

http://forum.slowtwitch.com/gforum.cgi?post=6040711#p6040711

  that's the upper headset bearing PN for all SCs, 2010-present, with the external steerer (aka bayonet style) fork. it's a custom
  bearing, so I'm not sure you'll find it anywhere other than through
  your Trek dealer.

  1st generation SC 7-series bikes (which technically were model years 2010-2013) that had a standard stem on a 1" aluminum fork
  steerer used a 1" cane creek upper bearing, PN 428420 from your Trek
  dealer.

I wanted to buy it online so I found it by the Cane Creek model #

http://forum.slowtwitch.com/forum/?post=4773430#p4773430

  The original SC7 upper headset bearing is a standard 1" threadless
  headset bearing with 45deg chamfers...your Trek dealer can order PN
  428420...Cane Creek PN is BAA0004K.

Ordered part BAA0004K from Amazon. That should do the trick.


Need guidance on selecting proper Gates belt drive components for my belt-ready frame I have a very cheap, locally made bike with a belt drive installed on it (the frame is belt-ready). One more thing to note is that the bike is equipped with SG-3C41 IGH from Shimano.

The problem is it's cheap for a reason - all stock belt drive components are some kind of Chinese cheap copies, and they perform quite bad (belt itself tends to fall-off often, and local bike workshops weren't able to solve this for me).

I would like to swap both sprockets and the belt itself for a brand new Gates belt drive set - while not changing anything else on this bike, if possible. But I'm getting completely lost when I try to figure out myself which components I need to order, and what size of the belt I need. So far I only figured that I need CDX line of components, and that SG-3C41 should be supported by some of them. I'm totally lost when it comes to details, and afraid I'll buy something that won't fit, as it's quite expensive.

Unfortunately, I'm living in a backward Eastern Europe country, and bike movement isn't very developed here. When I asked for help in a few local bike workshops, they said they don't have enough experience with belt drive either, and certainly are not able to help me acquiring them, as nobody imports those in here. They can only help with installing them, if I'll somehow buy them myself.

I'm ready to provide any exact measurements or additional details, if anybody is willing to help.

The Gates CDX system is supposed to be a bit better than the CDN, but they share the same belt and sprocket design. I believe the rear sprockets are interchangeable. CDC is a different design without the center guide.

You want the 3-lobe sprocket to fit on a Nexus SG-3C41 hub. Videos of how to install these are readily findable on the Web.

Without knowing what crank you have it's hard to give specific guidance. You need to know the bolt pattern and bolt center diameter (BCD) of your crank to find the right front sprocket.

The trick with Gates belt drives is that they are pretty sensitive to alignment of the front and rear sprockets. You need to know the chainline of the hub and sprocket and make the front sprocket on the crank match that. )Poor alignment may be why your current setup keeps throwing the belt.) If you have a square taper bottom bracket and crank you can adjust chainline by getting a different bottom bracket with a different axle length.


Difference between road pedals and MTB pedals I am interested in buying some pedals I can clip into for my bike. I currently ride a mountain bike/hybrid but I ma looking to get a road bike next year some time.

What are the differences between road pedals and mountain bike pedals? Are road pedals suitable for my hybrid/MTB if I am only riding on roads?

There are differences of opinion regarding what you are asking here. Some people are insistent that a road bike has to have proper road pedals, others think that for non-competitive riding over short distances the mountain bike style pedal is just fine, so long as you don't go all day in them and expect to win the Tour de France in them.

Let's look at the difference in shoes first. Road shoes have a huge cleat on the bottom of them that makes them not suitable for walking in off the bike. Meanwhile, mountain bike cleats are embedded in the sole and you can walk all day in shoes with them, just so long as you avoid polished wood floors that don't need to be scratched.

Cycling shoes have an upper and a sole. If you look at the market leading Sidi shoes the same uppers are available on both the mountain and the road versions. The soles are also remarkably similar, or at least the upper part of the sole. They have different rubber attached to the sole and different holes in them for the respective cleats.

Because of the different soles, with more rubber on the mountain variant, the best option for town riding is to get the mountain shoe. This is because you can ride them quite easily without being fully clipped in. With road soles this is not so easy to do, particularly in the wet, as you have to clip in properly before putting in any power strokes to get across that junction. They are also one-sided so you need to be adept to get into them. By contrast, you don't have to clip in with mountain bike pedals at all (if using Time Atac) and the cleat is always there for you as they have the cleat on both sides.

For where you are now, consider getting the mountain shoes, they have the same uppers and stiffness to the sole, if you pay for it (e.g. Sidi). You can also get more pliant shoes such as the Shimano affordable models that are stiff but not super-stiff. These can also be more presentable off-bike.

Remember that whatever pedal system you use the pedal, big or small still attaches to the same size hole in the chainset. Shoe stiffness with glass fibre or carbon fibre is huge so the platform size is not the be-all-and-end-all.

There is another choice to be made with the actual pedals. Shimano are the market leader with their SPD system, this has been earned not because it is a better pedal system. The other pedal system to look at is the Time 'Atac' range. This uses a smarter spring system that allows your feet to 'float' a lot more naturally. The 'Atac' pedal system is patent protected, the designer was the guy that designed the original road 'Look' pedal cleat system and I think it has a lot more going for it than the clunkier Shimano efforts.

Have a good look online for opinions regarding pedal choice/reliability and remember that most people defend their pedal system choice less than objectively. Generally shops will only stock the Shimano pedals or the 'Crank Bros' pedals and people that buy these will swear they have the best system.


What 1990's bike have I bought? I've not had a road bike since I was about 16 which is too many years ago to want to remember so forgive my ignorance.   I can remember that Cannondale were said to be good back in the day so I've bought one locally.  It was a fixer-upper so reasonably cheap.

I noticed having got it home that where the paint had chipped the colour underneath was a different colour. What's more it looks like a bit of surface rust.

Alarm bells are ringing and I'm wondering what I've bought.  I've spent hours trawling the web but failed.

This bike is said to be at least 20 years old. The bottom tube is tear-shaped and is slightly larger than the other tubes.

The other thing that makes this stand out for me is that the top tube has rolled at both ends slightly but 90 degrees from the other end. This means when you look at the bike from the side the top bar looks thinner, has a lower profile where it attaches to the head tube, whereas the opposite where it joins the seat post tube so from side on it looks wider, if that makes sense.

The serial number is S followed by about 7 or 8 digits and runs from back to front on the crank drive side. The forks are unusually straight too.

Can anybody put me out of my misery please?

That doesn't seem to match any Cannondale serial number formats.

https://vintagecannondale.com/info/serial_numbers/ says that there was a non-drive side placement for serial numbers, but they don't start with S.

That said, it seems to be a decent-enough looking road bike.  Simply add yellow paint to cover up the scratches, or perhaps contrast-paint over the damage with a different colour like deep black, or red, or ride it as-is.

The small support for the gear cable, lower on the head tube, is somewhat distinctive, and someone might recognise that.  Its not a cable-stop, it is just holding the cable outer.


Correct riding position on a road bike I've been riding my bike for a while it's a 55cm square frame. I recently used the online calculator on competitive cyclist. It told me I'd need a seat tube of 53 and top tube of 57cm.

So I'm riding a bike essentially too small for me...

It's not a massive amount out, so I'm sure I can tweak things for the correct position. Layback seatpost, slamming the stem etc.

--But what is the natural position on the bike to ensure no stresses on the back or wrists?

--What are the signs that something is too small?

The "natural" riding position would be one with the following criteria:

Your knee never fully extends (locks out) when the crank is at "dead bottom center"; basically in line with the seat tube
You can sit mostly upright when on the flat part of bars.  You have a comfortable slight bend in your elbow when on the hoods.  You can reach the drops without your knees hitting your chest/stomach/elbows.
When in either the hoods or the drops there is little upward or downward bend in your back.  Its just in a neutral, comfortable, position.
You feel no uncomfortable pressure on your perineum
Your knees are (relatively close to) over the pedal spindle with the crank arm level.

Obviously there are millions of ways to get this position depending on frame size, geometry, seat post height, stem length, handle bar drop, etc.  Not to mention your personal flexibility and level of fitness.

To answer your second question, you generally know a fram is too small if you must extend your seatpost beyond the manufacturers limits or you must use a stem that is longer than about 130mm or with a rise of more than about 12 degrees.

Any of these things should signal that you are trying to make the bike "bigger" by adding length to parts.

edit:  In regards to your comment about a "set back" seatpost, I would add this to the list of "ways you know a bike isn't the right size".  You are effectively trying to lengthen the seat tube.  Unfortunately, this will put your weight heavily on the back wheel and will effect steering/control.


Are BMX threaded headsets and other threaded headsets interchangeable? I want to buy a threaded headset for an old road frame that takes 1 inch threaded steerer tube / headsets.  I see headsets for sale online that are labeled as "1 inch threaded BMX headset".  Is there any compatibility issue with trying to install it on a road bike?  What about non-BMX-labeled headsets being installed on BMX frames?

I figure I can get a headset a little bit cheaper if I could use one that is labeled as "BMX".

No, they're not interchangeable. BMX 1" threaded headsets have an outer cup diameter of 32.7mm - they wouldn't fit in a standard road frame. Standard (ISO) threaded headsets have an outer cup diameter of 30.2mm - they'd fit loosely in a BMX frame.

Sheldon Brown's Bicycle Headset Dimension Cribsheet is a useful reference for headset interchangeability.


What cause and cure for tense or cramped stomach muscles? I recently restarted cycling to work. I did four round trips. After riding back from the fourth trip, my stomach muscles started to tense and cramp.

I heard that stretching before and after a ride, as well as remaining hydrated, could prevent this. Is there anything else I could do to prevent cramps? I intend on riding four days next week too because of the lively feeling I gain from cycling.

EDIT

There is nothing abnormal about my medical circumstances.

I ride 9mph on average in one direction (using cycle paths rather than roads) and slightly less coming back.

A one-way trip is under four miles.

Of course, as with any exercise, stretching is worthwhile. Mostly a few slow warm up laps around a short course, or taking it a bit easy the first few trips out, as you get used to riding a bike again. Mostly, try riding 2 or 3 days a week, with a rest day between, until you get fit enough to ride comfortably.


Options for carrying a smart briefcase on a bike (pannier or otherwise) Situation

I don't own a bike: however due to a recent change of office location, I have worked out that I could cycle in half the time as driving through rush-hour traffic every day. I'm therefore interested in the idea of purchasing a bike

Issue

I carry a smart laptop-size briefcase to work, which is just fine while driving - however I need to figure out how I would take it on a bike, if I choose to buy one. The briefcase is approximately 45cm long, 30cm high and 12cm deep. It looks similar to this one:

What I've thought of

I'm aware that luggage is normally taken on bikes by means of panniers. However it seems to me that directly attaching such a bag to a pannier rack by use of "spiders" (bungee cords) would be fairly unstable. The problem is that the pannier racks I have seen are usually pretty narrow (only just wider than the rear wheel); and therefore there isn't much of a stable "base" on which to place such a bag. The bag would have to lie flat - but also due to the limited length of a pannier rack, it wouldn't support the length of the bag - meaning that the bag would have to sit length-to-width. I.e the length of the bag would sit from left to right across the top of the rear wheel, only supported by a relatively narrow pannier rack in the middle. I can imagine that this would be fairly unstable.

From what I see, pannier racks are intended for especially-designed bags to be able to clip onto their sides - hanging down beside the wheel. However what does one do when one has an existing bag like the one above, which would not fit into one of those soft-sided pannier bags?

Does there exist some kind of pannier clip, or cage, which could attach to or contain my bag, to enable it to clip properly onto the side of a pannier rack?

Does any other solution exist which I have not considered?

It may be pertinent to note that my eye is on a folding bike - as I only have a small space in my shed, and nowhere to store a full-size, non-folding bike. Therefore any solution involving somehow mounting a cage within the frame under the crossbar would be impractical.

Any suggestions or advice appreciated

Depending on the thickness of your briefcase it may be a solution to hang it under the frame in the main triangle (if it fits there) but since you are thinking about a folding bike it is not a solution.

I've seen something else couple of times - a special carrier for briefcases:

I'm not sure how a folding bike would accommodate such a carrier as it attaches to the seat-stay and the back of the normal rear rack.

Another idea would be to put the front baggage rack and tie the bag there. Not only is this more stable (the bag is "in your hands") but you also have the bag (probably containing important documents) always in sight.

This is what I mean:

But again - folding bike limits your possibilities.


Choosing the right tube for my tire I wanted to change my bike tire. Is it okay to use 26x1.90 inner tube with 26x1.95 tire?

Inner tubes work over a range of tire sizes.  The difference between 1.9 and 1.95 width is insignificant for the tube.  Go ahead and reuse it.  You can look in the shop at what range the tubes claim to cover.  My quick look at one online store showed two tubes rated for 26x1.5-2.0, which cover your range, and one rated 26x1.95-2.25.  In theory you shouldn't have the last one, but I am sure it would work for 1.9 just fine.


Derailleur and back wheel alignment issues I've got a very old used bike. It has a bunch of issues I'm trying to fix at once: the derailleur is not keeping the chain tight only in certain gears, the back wheel wobbles slightly and over time gets pulled forward to the point of rubbing against the frame.

I took the wheel out and determined that there is probably some minor wobbling coming from something being off with the bearings but I decided not to take it apart, just live with it and try to put the wheel back pulled further back and somehow fixing the derailleur/gears issue too.

I figured out that there is one specific configuration when everything seems to work, see it on the photo below. (Note, the axle needs to be completely pulled back on the side pictured, but on the other side slightly more forward than that, that's the only way to have the wheel aligned with the line of travel at the middle of the frame). In this angle, the derailleur is able to keep the chain tight for all gears.

The issue is that now if I start pedaling or shifting gears, eventually the derailleur is forced to rotate counter clockwise and the axle is pulled forward so that I'm back at my original issues. I just can't seem to figure out how to maintain this specific position

How could I solve this?

Edit: I'm adding below a second image from a different angle

Update:

Thank you for all the comments and suggestions! Based on them, I plan to do the following:

Fix wobbling of the wheel by replacing bearings so that I'll be able to move the wheel forward
Replace the derailleur hanger and the mounting bolt attaching the derailleur to it
Use axle nuts instead of the regular ones and remove washers from the axle
Replace cable housing and possibly the chain too

To do the above, I'm having two new challenges:

How to unscrew the super tight and somewhat rusty current attachment of the derailleur to the current hanger? (see picture below)
Where can I find a suitable replacement mounting bolt that would allow me to attach the derailleur to the hanger so that it can pivot? (see part #2 and connecting parts in David D's answer)

That's one seriously chopped-around bike.  I see a bolt holding the rear derailleur on, on an axis that would normally pivot.   This means your B tension is non-existent or infinite depending on the gear chose.

I also see the hanger well out of position and missing its other bolt.  That means the derailleur is at a funny angle.  Attempted `shopping below:

Additionally, what's that brownish dish thing that is about where the smallest cog would be?  Maybe its supposed to be there to stop the chain dropping off the littlest cog ??

I suspect your chain will also be too long, once this angle is all corrected.

The gear cable outer also looks kind-of lumpy, as though the metal reinforcement is kinked or broken.  This may cause issues, or with friction shifters it may simply provide vagueness while shifting.

The wheel is sliding forward in the dropouts because its either not tight enough, or there's not enough resistance.  I think the axle nuts look like generic hardware store nuts, and will probably lack any serrations underneath.  Some time with a file could restore rounded serrations back to grippier ones, but really some new axle nuts would be better.

  This is your image, simply rotated so its about normal angle.  From this you can see how far back the derailleur is.

Here are some lines drawn on top of your image to show the angle difference:
  That empty little hole in the hanger is missing a special bolt, which stops it rotating around the axle and undoing your axle nut and holds the derailleur on when the wheel is out.

This is a conventional claw hanger - there is nothing special here, these pre-date all the unique weird custom hangers.  These are worth around $5-10 of most currencies - it would be easier to buy a new claw hanger than mess around trying to make that weird nut on the back.

  This mess is a mochup of where your derailler should be sitting, relative to the axle.  This position means there will be more teeth engaged at once with the chain.

Another realisation just now - you have a stiff link in your chain.

This results in a noticeable click or clunky every 4~5 crank revolutions, as this inflexible link passes through the derailleur's jockey wheels.  This is probably the point that the chain was closed up at fitting time, though it can be caused by dirt.

To fix it, grab the chain in your fists on either side and try to bend the chain sideways.  Start with enough force to open a loose jar-lid, and work up to a bit more if the chain doesn't come free in that link.

And finally - you say that the loose bearings are something to live with now.  I suspect this wobble is also contributing to the sloppy gears, because as the wheel moves it will move the whole cassette too.   I would totally recommend tuning up the bearings, and perhaps a clean and re-grease if you possibly can.

In summary - I think this is fixable.  It will never be perfect, but I'm sure it can be better.


Should flywheels on stationary trainers be replaced periodically to avoid catastrophic failures caused by fatigue? I have owned a Computrainer stationary trainer for 20 years and recently had the flywheel shatter, sending shrapnel through the walls and ceiling of my basement, as well as into my hamstring.  Should flywheels on stationary trainers be replaced on a regular basis to avoid fatigue-induced failures?  How often should a flywheel be replaced?

Apparently you are not the first victim of this problem:  http://www.saferproducts.gov/ViewIncident/1237585

I suggest you should also submit an incident report to the CPSC (assuming you are in the US).  Since you were injured you may also want to talk to a personal injury lawyer.  RacerMate's website claims they offer an "indestructable build".

The manufacturer should provide guidance on the safe use and maintenance of their products.  I'm sure they are aware of this type of failure.

Update:  the currently shipping Computrainer flywheel is apparently made of copper.  That sounds like it would be less prone to shatter.


Why do cyclists shave their legs? Why do cyclists shave their legs? Is it because of wind resistance?

Cyclists shaving their legs is more tradition than anything else--there is a whole industry around creams, soaps, and salves. However, I'll defer to Sheldon Brown's explanation for a few acceptable reasons why they do it:

To prevent infection when crashing.
To pull off bandages more painlessly after dressing a wound.
To get a massage of the legs without hair pulling.

One reason I've often heard is 'To be more streamlined in the wind'--but I don't believe it!


Is it possible to transport many (up to 12) bikes using some sort of auto-trailer? I would like to be able to use a trailer, either open-air or enclosed to transport multiple bicycles at the same time.  When I google hitch racks the maximum is 5...I am looking for a towable option...do these exist? Where can I find one?  Could I make one?

Where I live it is common for commercial operator to purpose build trailers for carrying bikes such as these.

The other option I have seen is custom bike racks for back of any flatdeck trailer or trucks.

One event here has over 1000 entrants to a relay - they need to transport 1500 bikes on the day, up to 100km..... So it's certainly doable.... I am glad I don't do their logistics planning...


Can a road bike stand constant 40km/h for long distances? I am planning on converting my road bike into an electrical one and I can see that I can get average speeds of 35-40kmh.  So I am planning on biking long distances at this average speed. Is it safe to do it? What can fail at such high speeds in long run, considering different types of asphalt quality. I know that it depends on the bike manufacturer, but can a generic failure be anticipated?

Stopping distance is definitely something to be aware of. As speed increases, the distance needed to stop increases non-linearly. For illustration, in cars, with 1 sec reaction time:

20 km/h = 8m
30 km/h = 13m (50% increase in speed, 63% increase in distance)

(Source: http://www.nzci.co.nz/tools-calculators/stopping-distances.html)

In other words, it may feel safer than it really is.

Also make sure your conversion has a brake sensor cutoff, you wouldn't want your braking distance increasing because the motor is pushing while you're frantically trying to stop.


triple chainring with with single speed freewheel I have a Hero Sprint Axis (with 18T freewheel).I ride mostly on flat roads, but want more top speed and a lower gear for starting from standstill. Is it possible to just install a triple chainring with no modifications to the rear freewheel?

Can i get this triple chainring online in India? (or any dealer in Kharagpur?)

On that particular bicycle you'll have to remove the chainguard. Depending on the configuration of that bicycle's drivetrain, you might have to swap crankset parts. Worst case, both crank arms, the chainring (for a triple), a new crank spider (if it's a separate piece), and the bottom bracket will need to be replaced.

It is possible that chainrings could be added on. It's difficult to tell without being able to see it in person.

Once you have that, you'll want to find something to act as a chain tensioner. There are purpose-built chain tensioners, but if one of those is not available, you can use a derailleur. Make sure whatever you're using can take up all the slack you'll have when you're shifted into your smallest chainring.

You'll also want to ensure that your middle chainring forms a straight chainline to your freewheel cog.

Another cyclist put together a 2x1 project with his Surly Karate Monkey here.

I don't know about the availability of parts in India, but if you find it's not feasible, you might consider finding a bike with a 3-speed internally-geared hub. It takes the chain tensioner out of the equation, requires no front derailleur, and comes stock on lots of bikes. Hub gearing isn't as cheap as derailleur gearing, but it's less susceptible to damage and corrosion and requires less maintenance over time.


MTB tires: why the extended thread on the edges? I have tires similar to this one:

My point is that the tire is quite "flat", with large knobs on the edges, unlike most MTB tires, which are round.

The tires feel quite unstable on any hard surface when cornering. What is the design reason behind making an MTB tire non-round?

These are downhill MTB specific tyres. The extended side knobs will fully engage when cornering hard. By hard I mean:

http://www.pinkbike.com/photo/6705085/
http://i129.photobucket.com/albums/p223/XCSlayer/DSCI4707.jpg

The large gap between the center and the side knobs is mainly to reduce weight and to improve the mud management of the tyre (to not allow mud to be blocked and carried between the knobs).

A review of the specific tyre you posted can be found at http://www.pinkbike.com/news/Maxxis-Minion-High-Roller-2-review-2011.html and for the side (cornering) knobs it says:

The cornering knobs were altered with this in mind, angling them slightly
for more bite and adding a vertical sipe, again for added knob flex to
allow them to conform to the ground better than a solid knob. Changes
were also made to have the cornering lugs bite sooner than on the
previous design.


Issue replacing Avid BB7 disc brake pads I just replaced the brake pads in my BB7 disc brakes for the first time.

I read up, watched videos, til I grasped what I was doing, and tried more than a handful of times. On the front brake, I can clearly see (with the wheel removed) that the pads are in a V position -- having a narrow gap further inside (the part harder to see), and a wider gap towards the outside. I assume this is just because of the way they sit around the spring.

The problem is, while the narrow part of that gap is (barely!) wide enough for the rotor, I can't get the rotor lined up in it properly. Even when the pads are dialed all the way out, and the caliper bolts are loose, it's hard to manually align it so there's no rub.

So, I tried all kinds of approaches, but in the end, here's something that doesn't seem right, and I can't figure out what's up:

1) Loosened caliper bolts
2) Turned pad dials all the way out
3) Turned outside pad dial all the way in (this was an experiment, I know it's not the right approach)
4) Turn inside pad dial til rotor is snug
5) Tighten both caliper bolts, a little at a time
6) Turn both pad dials all the way out

Even in this case, it was the outer pad that rubbed against the rotor and the inner one had a big enough gap. Again, I know that's not exactly the right approach, but after not getting the outer pad to pull back enough off the rotor, I tried this, and am not sure where to go from here, since the outer pad still won't back off enough.

If only one brake pad rubs and there is a gap between the rotor and the other pad, then your brake isn't centered well. To fix it:

Use an allen key to loosen the caliper so that you can slide it around but it is still attached.
Pull the brake lever. This way, the brake goes into a position centered around the disc.
While still holding the lever, secure the brake again.
Release the brake lever and find out that your brake doesn't rub any more!


I am about to buy a new bicycle - what should I check before I do so? I'm not really a pro in bicycles, I barely know the basics about the construction itself, but I love cycling. I've been cycling on my old bicycle for 2 months now and I love it.

Unfortunately, my bike has broken down today, so I need to go to our local shop and buy a new one. I bike on roads, or on easier hills, sometimes on a rocky trails, but nothing really crazy or extreme.

What should I look for when buying a new bike, what should I want, or what should I not want?

I expect to spend about $500 and I really don't want to get ripped-off, or buy a bike I don't need for my trails.

I would go further than posipiet: find a good bike shop and do what they say. They know exactly what bikes are available and how those bikes work in your local area.

I suggest thinking very carefully about suspension. On a bike that cheap you will not get good suspension, so the question is whether you would rather have poor suspension or better parts. The money that goes into the suspension comes from the rest of the bike - everything else is a little bit cheaper.

Buying second hand is definitely a good way to save money. There's more risk of getting a bad bike, and you need to be careful about bikes that are cheaper than they should be  - they're probably stolen. The difference between a bargain and a thief can be hard to tell. Checking the frame number with the Police is about all you can really do.

What type of bike do you want? The choice is between a mountain bike and a hybrid, I think, although you could get a cheap racing bike for $500. But if you ride offroad at all the racing bike will not work, so Iĺl ignore that.

The hybrid bike will have thinner tyres, a more upright seating position and be slightly lighter. You will go slightly faster on it, but off road it will not work as well.

The MTB will be lower, longer and have fatter tyres. It will be less comfortable but perform better off road.

Like suspension, disk brakes look cool and all the expensive bikes have them. But again, cheap disk brakes cost more than cheap V brakes so that extra money means everything else is a little bit cheaper. They will probably work better than V brakes, but cost more to service. But they might not need servicing as often.

Also consider spending some money on accessories. At least lights and a rear rack, possibly mudguards as well. Buying panniers is probably out of your budget, but those will make commuting a lot easier. The idea is to get your load off your back and onto the bike.