Where to buy bar end shifters I would really like to pickup a pair of bar end shifters but none of my local bike shops are able to get any for me.  My local bike dump laughed in my face when I asked them where I should/could find them.

Where online could I get some bar end shifters for a reasonable price?  (Bonus points for cheap shipping to/in Canada).

The first place I look for 'unusual' parts is Loose Screws. They have Ultegra and Dura Ace bar end shifters available.

My second source is Rivendell Bicycle Works - They have a couple of different options.

Not sure what you consider a reasonable price, but $100 US seems to be the ballpark for new shifters.

Finally - you can always try eBay for used parts, but that is hit and miss for both quality and selection when dealing with more obscure parts like these.


How to fasten main cable to BR-CT91 (Shimano Altus) brake? Basic question, but it isn't addressed in instruction manual that came with the brake.

In picture, (from left to right), there is the brake, a bracket, a rubber washer and a nut.  Where do I a thread the cable through?

The cable is threaded underneath the L-shaped bracket, in the corner of the L. The cable is clamped between the bracket and brake body.

You may see a shallow slot for the cable in the bracket at that point.


Need help with picking right shoes for riding my new bike I haven't been on a bike since I was a child.  I have had had weight-loss surgery due to being extremely over weight.

I now have a bike but my feet keep sliding off the pedals or just don't feel secure so I've been looking into the different types of shoes.

I have a basic mountain bike I can't afford to buy shoes plus new pedals so my questions is what are the best affordable shoes to wear on normal pedals so I don't keep losing my footing?

You may look at changing your pedals, instead of your shoes.  Many companies make flat pedals with pins to keep your foot/shoe on the pedal.

Keep in mind there are trade offs.  Your current pedals may have no grip, but you can probably ride them barefoot, in flip flops, etc.  More agressive pedals will most certainly keep your feet from sliding off, but are also famous for causing shin and leg injuries when they catch you unawares.

You may also look at cages which will hold your feet in place as well, but are a bit harder to get out of (meaning you may get your foot stuck and fall).

Either of these styles of pedals should be purchasable for about the same, or less than a new pair of shoes, and should likely last longer than any cycling specific shoe.


What's the rubber tube in my puncture repair kit for? I've got an old school puncture repair kit, the type with glue and patches.

As well as the sandpaper, patches, 'vulcanizing fluid' and instructions, there is a 2.5cm long, 3mm wide, beige rubber tube.

What's it for?

(it doesn't seem to appear in the pictorial instructions)

It is the Dunlop valve, it was used a lot in Holland, UK, etc.
You can see it in action here:

But currently it is replace by the Blitz:


Adult tandem trike conversion I'd like to take my old tandem and make it a trike with dally tires and rims on the rear. Has anyone done it. Thanks

There is a front-end trike conversion system called the Newton that has been used for tandems. I have no direct experience with it.

There are a number of rear-end trike conversion systems that are all similar in design: the Trykit and Longstaff. I know that Longstaff has built tandem trikes from the ground up, although I don't know if their conversion kit is suitable for tandems.

You may note that these companies are all in the UK. Triking is much more established there.


How do I tune up the shifters/derailleurs on my mountain bike? I have a Diamondback mountain bike with Shimano shifters that I bought used last summer, and over time the shifting has gone out of whack. For example, on the front wheel I can't shift into the easiest gear, and in some gears it sounds like the chain is rubbing on one of the derailleurs when I'm riding. Also when I'm in the hardest two gears on the back wheel, the chain slips sometimes.

I've tried adjusting the screws on the derailleurs and got the rubbing noise to go away, but it returned not long afterward.

I ride my bike to work but wouldn't call myself a cyclist. How would you explain to a child, step-by-step, how to tune up the bike's shifting? How do I know if a part needs to be replaced, and are there any parts in the shifting system that I should expect to have to replace after riding the bike 1000 miles?

You said to explain it as if to a child so here it goes.
Basic Shifter/Derailleur concepts: The derailleur spring is always pulling to the smaller ring(s). Assuming your bike has Trigger shifters since you said it was a MTB, the big thumb lever will push the derailleur to the bigger ring(s). This is true for both front and rear (left and right respectively). The trigger is basically a "catch release", letting the spring pull the derailleur to the next smaller ring.
Setting the Rear Derailleur (RD):
Preferably with the bike in a stand, but can be done upside down, get the RD into the smallest ring (pull trigger until it stops clicking).
Start turning the pedal with your one hand and push the thumb lever to shift to the next bigger ring. If it shifts smoothly and quickly, push the lever again, etc.
If, after you shift, the chain doesn't bump to the next cog, find a barrel adjuster and turn it as if you were loosening it (CCW) while still turning the pedals. You are, in essence, lengthening the cable and pulling the RD toward the bigger cog (inboard).
Once you get to the biggest cog, pull the trigger so that it starts to shift toward the smaller cogs.  If it doesn't drop down, you'll have to turn the barrel adjuster as if you were tightening it (Clockwise) effectively shortening the cable and letting the spring pull it farther outboard.
Front Derailleur (FD):
The process is similar to the RD. Shift so that it's in the smallest ring (pull the trigger).  Once there, inspect the cable.  Note how much slack there is. If the cable has a lot of slack (no tension), try to find the barrel adjuster and turn it CCW (loosen/lengthen) until there's only a very slight amount of tension. If the cable it still taut, I like to shorten the cable (turn Clockwise) until there's very little tension.
From there, turn the pedals with one hand and push the thumb lever on the left shifter.  If it goes to the next ring, sweet.  If it's having difficulty, I stop pedaling, turn the barrel adjuster CCW, then shift back to the small ring (pull the trigger), then start pedaling and push the thumb lever again. Repeat until it shifts cleanly.
Adjusting the limiters:
Both RD and FD have limiter screws that limit (obviously) the boundaries of the the derailleurs.  They will most likely be Phillips head.

They keep the RD from going into the spokes or dropping the chain between the cassette and the wheel. On the FD, they keep the chain from dropping in off the small ring or out off the big ring.
FD: Shift to your hardest gears in front (biggest ring) and back (smallest ring). Many derailleurs will label the screws with "High" or "H" and "Low" or "L". High = Hardest/Outboard, Low = Easiest/Inboard. The way the gears are now, you'll be adjusting the "H" screws.  If they aren't labeled, you'll have to look and see which screw is actually hitting, or nearest to hitting, another part of the derailleur. Adjust the FD so that the outside of the FD is about 1mm from the chain or as close as you can get it without rubbing. (The latter for cheaper cranksets that develop wobbles in the chainrings).  Adjust the RD so that the cage and pulleys are parallel with the smallest cog.
Now shift so that the RD is in the Biggest Ring and the FD is in the smallest. This is your easiest gear or fully inboard.  Now using the other screw ("L"), again, adjust the FD so that there's about 1mm space between the derailleur and the chain or until there's no rubbing.  Adjust the RD so that if you pull the cable with your hand it moves no more than 1/2 the width of the chain.  Just enough so that it can shift to the big cog easily and stay there effectively.
If there are still issues, there could be other things at play. You might have to replace housing or cables.  Maybe your RD hanger is bent.  Maybe your FD is askew

Hope that helps.


Attach bottle cage to frame w/o mount screws I'm planning on getting a bottle cage for my bike, but my bike does not have the standard mount screws for one. As I understand it, there are two types of cages: bolted cages and clamped cages. I'd prefer a bolted cage because they are cheaper ($5ish vs. $10ish).

Is it possible to drill holes directly into the frame for the bolts (I do have a good bit of experience working with aluminum)? Are there any other alternative methods for attachment, or would I be better off with the clamp cage?

Yes, it is possible to install a set of water bottle "braze-ons" on a frame which was not originally supplied with them.

It requires a very specific set of tools and parts.

The video below shows how a Rivnut works.

The second video wexpolains how to install a set in a bicycle frame.


Will Sram GX Eagle grip shift trigger work with 11sp cassette? Will Sram GX Eagle grip shift trigger work with 11sp cassette? Is it possible to adjust it so that one click in shifter is just useless. I am upgrading my transsmision. I can't afford buying whole eagle set at once (power meter is more important now ;) ) but this solution seems a little more forward-looking.

Unfortunately it will not work due to the cassette spacing, even using an 12 speed shifter and derailleur, it will not shift correctly due to the increased space of the 11sp cassette which has 3.8mm between cogs while the 12sp cassette has 3.65mm between cogs.

  [For a 12sp cassette] The spacing between cogs has been reduced, from 3.8 mm to 3.65 mm, and the 50 tooth cog cups the drive body more, thus bringing it closer to the spokes

  ....The shifter had to be redesigned to provide for 12 clicks and to incorporate revised cable pull to deal with the narrower cog spacing.

Source


Unobtainium headset size? This summer I took apart my old mountain bike to do a rebuild. It is a Raleigh Legend, from Raleigh Canada, circa 1994. When I got to the headset, I looked for a replacement but it seems the combination doesn't exist. It is a 1" threaded headset, but the diameter of the pressed-in part of the cups (and corresponding ID of ends of headtube) is 34mm. It seems headsets for 1" are intended for 30mm cups, and to get 34mm cups the headset is based on 1-1/8". I thought perhaps there would be a way to deal with this with circular shims, and I do recall seeing some online, but as I remember there was still an issue with the crown race ID, so in the end I reused the headset parts but replaced the balls.

So the question is, is the only way to put a new headset on this bike to replace the fork with one that has 1-1/8" steerer tube (which also means new stem and possibly handlebar)?

The product you are looking for is called "headtube adaptor" or "headset reducer". Once you know the name, you should be able to find them online.

If the headset is in good shape, there should be no reason to replace it. Rebuild usually refers to cleaning, greasing and adjustment, and possibly replacing bearing balls.


Upgrading parts on Fuji Panic 3.0 I want to upgrade some gear parts on my current bike, which is a Fuji Panic 3.0
I don't really know if it will be compatible though.
The bike: http://www.bikepedia.com/QuickBike/BikeSpecs.aspx?year=2006&brand=Fuji&model=Panic+3.0

Parts i will be equipping/replacing with:

Shimano Alivio ST-M4000 Shifters 3 x 9-speed
Shimano Deore RD-M592 rear derallieur MTB SGS
Shimano Deore FD-M590 front derallieur Top Swing OR FD-M591 Down Swing
Shimano Alivio CS-HG300 Cassette 9-speed
Shimano Alivio FC-M4000 Crankset MTB 40/30/22, 9-speed

Parts are not final, i can for example replace the M592 with a M591 for about €5 cheaper

I also noticed that some of the parts come in diffrent versions and designs, for example the cassette comes with different ammount of cogs: 11-28, 11-32, 11-34, etc.

How do i know which designs/versions to use? The Crankset (some length in mm), Front derrallieur (some angle in degrees) and rear cassette (ammount of cogs) have diffrent versions

Is there any other parts i would need to buy? I was thinking i could re-use the rest on the bike.

Everything on the bike except the shifters are original. I could also just buy Claris shifters and use current parts but since i bought the bike used and the gears seem somewhat clunky i decided it might be best to replace the gears instead.

Thoughts?

Thanks in advance!

/C

EDIT: The parts will cost around €160

EDIT2: Thanks for all the answers, I will be buying a new bike.


Wrapping alloy brifters for cold weather I have a bike with alloy brifters that get very cold during winter season riding.  I wear a nice pair of gloves and the cold comes right through because my hands are wrapped around them and usually in constant contact with some part of the alloy brake lever or the alloy shift paddle (Rival 22 Hydro).  This gets uncomfortable, as I'm sure many others have found while riding in the cold.

This is not a problem at all when I'm riding my bike with carbon and/or plastic brifters.

I know why this happens and my question is what and how can I wrap the levers with in order to mitigate the conduction from them to my fingers in cold weather?

I'm concerned with interfering with the motion of the paddles and levers.  I don't want them to be sticking or missing shifts because there is some bulky tape wrapped around them.

Are there any materials and methods others have used successfully? Also, I'm not really interested in bar mits as a solution.

Do you care about originality ?  Consider changing the brifters for something made from plastic or carbon because as you've noted, they don't suffer the same issue.  Likely to be an expensive solution.

So, can you paint your brifter's outside surfaces with an acrylic enamel paint?  you'll need many thin coats to build up a thick layer that won't abrade easily.  Sand between coats and add some clear coats as the top layer.  Avoid painting "under" the brake lever where it faces the gear change lever.

Instead of paint, you might choose to use a product called Plastidip, which historically was used for dipping tool handles, but more recently comes in a spray can and has been used for car wheel rims, etc.  This stuff comes in multiple colours.

You can also get sticky-backed cork tiles/sheet which is under 2mm thick.  Some creative pattern work and you should be able to put some heat-insulating cork between you and the cold bits.  Do apply sealant/varnish to the cork to protect it from the cold.

Leather is another valid alternative to cork.

Finally, you wear gloves already, so assume they are full-finger.  You could add heating wires to the gloves and run them off a small USB battery in your back pocket, or add heating wires to the brifters themselves and mount the battery on the bike frame.

If you do get a choice of colour, I'd suggest black, or as dark as possible to increase heat insolation from any sunlight.


Seatpost Overextension I've been riding with my very short seat post extended well past its maximum extension line for quite a while now. Looking at the seat post itself I don't see any signs of deformation or damage other than some very minor surface rust.

Could my bike frame have been damaged? Could the lever force have damaged the frame? I can post some pictures of the frame if needed. My bike is all aluminum.

Pull the post and hold it next to the seat tube to see how far it goes in.

If it does not go in far enough to be into the seat tube below the top tube you are putting a LOT of stress on the top of the seat tube.

Believe that maximum mark on the seat post.  A seat post is not that expensive to risk damaging a frame.

This is just one (not cheap) seat post but that min mark is pretty conservative.  If you are cheating the min mark you playing with danger.


What's the inner width of my rim? I just measured the inner width of my rim with a ruler and it seemed to be a hair over 14mm.  Looking at the tire sizing chart on Sheldon Brown's site it doesn't have an entry for 14mm inner width rims. My wheels are Vuelta Corsa HDs (nashbar special), and that rim is probably used on other Vuelta wheels, so I'm thinking it's not an unusual size. Might they be considered 15mm? Anyone know the official spec for those rims?

Nashbar's specs for the rim list the inner width as 16mm.
http://www.nashbar.com/bikes/Product_10053_10052_566766_-1___
(click the "Specs" link)

This is a fairly standard width for road wheels, so you should be able to safely run any common road tire size (21mm-35mm give or take a few mm).


Do high and narrow seat and back bending provide good bike riding posture? I would like to ride a bike as part of daily commute on roads someday, as I  rode a bike to school in another country in the past. But I have been bothered by some uncomfortable points from the bikes that some or most people   ride in US. I value safety (both transportation and health) more than speed, but I guess that my different biking experience may be "old-schooled" and have rendered me ignorant about the biking reality in US.

I have seen some people adjust their seats  high. When I  sit on  their bikes, my feet can't touch the ground.
The reason why I want to land my feet on the ground is that I want to ride a bike in city traffic, where I often need to stop and restart biking. I was wondering how I can stop safely and easily without landing one or ideally both of my feet on the ground while sitting on a high seat?
(In US, most roads don't have bike lanes, and many car and truck drivers are not  used to driving past bikers, and may unleash  road rages towards bikers who block or partially block their ways. Some suggest to ride in the same lanes as cars, so that bikers can be noticed more easily by automobile drivers, but I will probably still ride to the rightmost as if there were bike lanes on the roads, even though that can mean that there are more  chances for irregularly-shaped small stones to damage the tires of  bikes.)

Some bikes have very narrow and small seats. Aren't they together with their high positions putting greater pressure on the crotches than slightly wider and bigger seats?

Also some people bend their backs forward when riding bikes, just like in Olympic bicycle competitions. That together with their high seats puts their butts in  more prominent positions than  their backs   straight-up or only slightly leaning forward. Isn't bending backs forward harmful for their backs?

Thanks.

You don't have to do any of these things to commute. If you value safety over speed I'd recommend a more upright bike (Dutch style) which
helps improve visibility and makes it easier to look around. They also allow you to ride in the clothes you want to wear at your destination. What you call old-school is current every-day practice in a lot of Europe.

You could lower your saddle so your feet can touch the floor but this isn't an ideal riding position usually. What would be more ideal is learning how to stop and set-off properly. You need to hop out of your saddle as you come to a stop and put your non-dominant foot down. Then use your dominant foot to put its pedal near to front and top of the stroke. When you set off you push down with your dominant foot on the pedal and at the same time lift yourself back into the saddle.

The saddle should support your sit-bones (at the bottom of the pelvis) which in men aren't all that far apart, hence the narrow saddles you see. However a hunched over riding position also means less weight is put on the saddle and more on the hands and feet than when using a more upright bike. Wider saddles can be more comfortable when you have more weight on the saddle but can be detrimental on longer rides. Your saddle type may depend on your commute length. Generally cheaper squidgy saddles are made to entice people by looking comfortable but are actually worse than a firmer, narrower saddle which is designed to support your sit bones properly.

You also mention riding in the debris-strewn area of the road. Another advantage of Dutch bikes is that they're designed to be robust, with heavier, wider, reinforced tyres.
I would recommend looking into various techniques for positioning yourself in the road, but I can't offer advice on the US since the streets are designed very differently from Europe. Hopefully there are US-specific resources out there.
Edit: I forgot to mention mirrors. I recently changed bike and my new one came with a mirror mounted on the end of the handlebars. It's helped enormously with being aware of my surroundings and traffic, so I'd thoroughly recommend one. Presumably a helmet-mounted mirror would be the same.


What is a good way to keep my tires from going flat easily? Title says it all, how do I keep my bicycle tires from going flat easily? I live in an area with a lot of sharp stuff (think glass shards, nails, cactus, etc)...

There are a number of things you can do:

Puncture resistant tires.  These have kevlar/aramid belting in the tire, thicker rubber or other features that make them harder to puncture. Would need to know more specifics about your bike (especially wheel/rim size) to be able to suggest specific tires, but Specialized, Continental, Schwalbe, and pretty much every other major tire manufacturer have a wide range of puncture-resistant tires. You can probably just go to your local bike shop and ask about puncture resistant tires, or you can order them online a number of places. There's a bunch of good suggestions here for specific types: What type of tires can prevent goatheads?
Puncture resistant tubes.  These seem to be harder to find.
Slime/goo in the tube.  Personally I don't care for this, but some people swear by it.  This is a sort of thick goop that goes inside the tube; small punctures will get filled in by the goop.
Tire inserts.  These are kind of like a belt that goes between the tire and the innertube, stopping sharp pointy things from going into the tube.
Keep tires well-inflated (near the top of the recommended pressure).  This reduces the size of the contact patch and makes it more likely stuff will glance off the tire. You didn't mention them in the question, but this also prevents pinch-flats.
Avoid riding over sharp pointy things, especially when there's water around.  It's much easier to cut or puncture rubber when wet, since dry rubber tends to grab glass and metal.

Also, if you do get a flat, make sure to check both for remaining pointy bits and gashes in the tire large enough for the tube to herniate out through.


Why/how did flat bars take over? Is there a verifiable reason for the ubiquity of flat bars on bikes these days?-- if so, what is it? It seems that 90% of the time I see people riding a newish bike that isn't a Dutch bike/roadster, they are holding their arms straight out in order to grab onto some flat piece of metal covered in rubber. Moreover, if it's a typical "hipster" bike (i.e. an older frame possibly with newer components), even if it has drop bars, the brake levers are not typical "drop-bar-style" brakes but are rather mounted horizontally along the bar tops, meaning that the hooks are more or less useless because you can't brake from them, and the drops are even more dangerous because it's just not possible (for me at least) to quickly move from the drops to the tops quickly while keeping myself stable (My Google-fu doesn't seem to be good enough to find a photo of this phenomenon online).

Flat bars are easier to learn on than drop bars (unless the latter have interrupter brake levers). At this stage low speed manoeuvrability matters more than efficiency. Some people with small hands apparently have trouble braking firmly from the hoods and getting into the drops is tricky for a novice (I dismiss starting in the drops as I've never got on with it). Then people like what they're familiar with if they lack a pressing reason to switch. Drop bars - as you said - need to be right to be comfortable, and the riders who get even the most basic bike shop fitting (not good enough for road bikes really) are in the minority.

Some people (e.g. me) like the extra height of flat bars for seeing and being seen over cars.

Cruiser bars (apart from being a horrible angle for your wrists if the top tube is on the short side and/or you have broad shoulders) lead to odd handling on some frame geometries, and make it hard to stand up on the pedals. So they don't work for MTB use. And MTBs have sold well since they went mass market (including in BSO form as evidenced in a recent question here). This may have something to do with the forgiving geometry - including the hands position. Don't underestimate the value of a bike that doesn't need much fitting (just saddle height) to be adequate.


What are the good bicycles available in India I want to start cycling on weekend around 10 KM on road. I am not sure which bicycle would be best for me ? I do not want to invest much amount in it.

I am in India . Can anyone suggest a good bicycle which I should buy ? It should be on amazon.in

getting a new bike might be troublesome as it is a huge investment, but here are some tips that I always give others.

Get to know what kind of terrain you will be riding. There are road, trails and hybrid.

This may be a very hard factor to decide, hence many of us would recommend you borrow or rent a bike and test which suits you. Road cycling are easier and can travel further and more towards training your speed. Trails are more towards pushing yourself to overcome obstacles and about having fun. Hybrid you can do both but not as great.

Are you willing to spend on your hobbies?

Investing in a bike is a expensive hobby, really expensive. Getting a bike that can repair easily is the most ideal. For example, you should look for bike that has parts can be found online easily. Getting a bike that is impossible to find a replacement part will give you headache as you might have to spend more or get a new bike.

I am not from India so I cant give you my opinion but if I were you, I would get a mountain bike, which has a front suspension. DO not jump to getting a full suspension immediately tho. I favour mountain bikes more as you can swap the tires for road and swap it back for mountain bike trails where u can explore more stuff. this is just my opinion, hope it helps. you can ask me if you have any questions. :)


Ultegra on Trek Crockett 5 I have 2 questions regarding the switch to Ultegra. I already have Ultegra 32 cassette on my Trek because I build another set of Vision road wheels.

Would it be possible to switch completely from the SRAM Rival that I have at the moment to 2-11 Ultegra system ?
Would it be possible to just switch the rear derailleur and the shifters (already have Ultegra cassette) but leave the Rival crankset in order to have a 1-by-11 system?

Answering this: 'but a full Ultegra system 2x11 can be placed on this frame, right?'

Yes. Frames are not made specifically for either SRAM or Shimano groupsets.

As mentioned in comments you will have to swap out the shifters, rear derailleur and hydraulic brake calipers. Shimano rotors will be compatible I believe.

For the 1x option the SRAM crank can be left in place. The only difficulty I see is that I'm not sure if Shimano makes an Ultegra non-shifter front brake lever unit. You could use a regular shifter/brake unit of course.

For a 2x11 you will need a clamp on front derailleur, and a compatible crankset. It does not have to be a Shimano unit, you could use another vendors products such as FSA.

One thing to consider. Swapping out a whole groupset is expensive (taking into account cost of components and installation). You may find that selling the Crocket and buying a Ultegra equipped bike is the better option.


Are chainring bolts alone strong enough? Because of a custom application, I need to be able to use 104BCD chainrings. However, I need a stand-alone spider to hold the chainrings; the chainwheel will not be mounted directly to a 104BCD crank.
The only 104BCD spider that I can find is the Profile Racing BMX spider, which has a hole that is too big for the spindle it will go on, and will require machining to adapt.
https://www.amazon.com/Profile-Racing-104mm-4-bolt-Spider/dp/B001GSQQDA
I have access to a laser cutter, so I can have a 104BCD spider cut out of plate steel with the size of hole that I need. The problem is that for a spider made from a plain piece of plate steel, there is no "ridge" machined into the spider to hold the chainring centered. The chainring will be held to the flat spider entirely by the chainring bolts. This is a little different than usual because most cranksets and spiders have machined ridges to hold the sprocket, and the chainring bolts only take part of the load. The question is, are chainring bolts alone strong enough to hold a chainring? Should I use steel chainring bolts?

I assume by 'ridge machined into the spider to hold the chainring centered' you mean the edge of the shoulders machined into the spider arms.

The edges are not there to position the chainring nor transmit torque. The chainring bolts do that. Remember the force transmitted to the chainrings by the bolts is perpendicular to a radial line drawn through the spider arm.
The chainring bolt holes in your spider need to be accurately positioned and sized to accept the bolts. I doubt laser cutting will achieve the required accuracy for the holes and these will need to be machined.


Shimano XT with Campag Centaur crank? I would like to use a Shimano XT group for my flat-bar disc-brake touring bike, but the XT crankset doesn't suit my touring needs very well. I would prefer having a 50/34 crank instead of the XT's 38/26.

To what extent is is possible to just change the crankset? I would like to keep the XT shifters etc., it's just the crankset that needs changing. Specifically, I'm considering putting on a Campagnolo Centaur Red&Black 50/34 crankset. Would this combination work? Does anyone have any experience with this or a similar setup?

Thank you very much for your answers!

There are a few things to keep in mind.

Will the current front derailleur work with the new chainring sizes?

If you have enough adjustment range in the position of the front derailleur,      this can almost always work with a double chainring. However, it may require some grinding of the cage on the front derailleur. The outer edge of the cage needs to
match the curvature of the outer ring and the inner edge needs to clear the smaller chainring when the chain is on the big ring. I think the XT derailluer can work, but Shimano also makes a flat bar component group that might better match
the crank. Shimano Flat Bar Road Group
The new crank will require a different bottom bracket, does the new crank work with the size bottom bracket on your bike?

Most MTB's have a wider bottom bracket, 73mm vs the 68mm common on road bikes.
Depending on the exact configuration of the crankset and axle you may be able to solve this with spacers, but the cranks need to clear the chainstays. For a "touring" frame this should not be a problem, my guess is that it would come with the 68mm standard BB width.
Does the rear derailleur have enough capacity to work with the new gears?

The capacity is (Big - little front)+ ( Big - little back ). 50-34 = 16, 38-26 = 12. That should not be enough of a change to matter.


hybrid bike ... too small? risks? I bought a Schwinn from a big box.  I'm regretting it for technical reasons (shifters, brakes), but I'm starting to wonder if the frame is too small.  I have the seat way up and going down steep (paved) hills is a bit scary.  It feels a bit unstable.  It's a hybrid because my wife and I like to go on the C&O canal every now and then, but I am starting to put the miles on the road when riding alone (see the aforementioned hill... we have LOTS).  At 6'1", with a 33" inseam, should I have concerns about this 17.5" frame?

There is danger and there is discomfort...you should accommodate both.
There is a max insertion line on the seat post - do not ride the bike with the seat post extended beyond that line, buy a longer seatpost. Though I would imagine that a standard 17.5 frame would accommodate a 33 in inseam (is that your real inseam...or the length of trousers you prefer? There is a difference).
If the reach to the bars is too short, bringing your hands too close to the hips for your center of gravity, then you will feel that you don't have a lot of steering control.
It sounds like the bike is too small for your comfort - some people like small, whippy bikes and others like to ride much larger, more stable, bicycles. People are usually more comfortable on a larger bike, where they can change position during a longer ride and as the terrain changes.
Good luck, and have fun riding!


How do I revive my front shock? I left my mountain bike hanging from the front tire for a long time. Now my front shock is seized. What should I do to fix the shock? I'm considering spraying it with WD-40, but I'm not sure if that will further damage the shock.

I can attach a picture of my shock if that would be helpful. The shock is close to 20 years old too if that matters.

Manitou mach 5 sx answer cartridge shocks

Depending on the age, personal attachment, and value of the fork, you could have it rebuilt at you local bike shop. However with it being close to 20 years old you might be just as well suited to purchase an inexpensive replacement fork.

You should be able to get something like a Suntour for a relatively inexpensive amount. You might check your local classifieds for a used fork as well to save some money. Weigh how often you use (or plan to use) the bike against how much money it would cost to replace/rebuild and decide if it fits your budget. No need to pay $100 to hang it back on the ceiling for another 20 years :)


Titanium frame: using copper grease I just took home a shiny Van Nicholas Amazon frame. The bike shop provided me with some copper grease and told me to apply it on the bottom bracket, otherwise the frame would suffer from "cold bonding" over the years. Looking further in to it, I read that is best to apply it on every metal to titanium contact. I want to keep this frame for life, so I think this is important enough.

Question: does that go as well for :

the length of the seatpost that sits in the frame ?
seat clamp ?
bottle cage bosses ?
rear derailleur ?
front derailleur clamp ?

And, should I apply it wealthy or just a thin coat is enough ?

Edit: here is how I used the copper grease :

I would say yes, use copper grease / ti prep / anti-seize on any titanium-to-metal contact (and especially ti to aluminum) that you anticipate staying put for a long period of time.

Length of the seatpost - yes
Seat post clamp - yes
Bottle cages bolts - yes
Rear derailleur - yes

The front derailleur clamp seems more questionable because it isn't threaded or a tight fit in theory, but sure, why not? Applying liberally is better— you want the copper grease to stay put through washes and rain to do its job.


Can I use a Center Lock hub and disc brake rotor in place of an ISO hub? I currently have a regular ISO disc brake hub and rotor on my front wheel. I'd like to replace it with a Shimano generator hub, but all Shimano hubs use Center Lock rotors instead of ISO. The Center Lock to ISO adapters seem really hokey, so I was thinking I could just get a new Center Lock rotor of the same size.

I don't know how to tell if the left-to-right alignment of the rotors is the same between the two mounting standards. Will this work without any additional adapters or modifications?

Yes, this should work just fine. CenterLock and ISO six bolt wheels should be interchangeable w/o problems as long as they use the same rotor diameter.


Disc brake equipped time trial bikes in grand tour Why did team Deceuninck–Quick-Step ride disc brake equipped time trial bikes in a relatively flat course through Brussels in stage 2 of the 2019 Tour de France?

The main reason is the 2020 Specialized Shiv provided by their sponsor is only produced in a disc version.

You can see an article about the bike here:
https://www.bikeradar.com/news/specialized-sworks-shiv-tt-disc/


How to attach graphics to frame For attaching graphics to a painted metal bike frame, is there a better option than Scotch tape or clear packing tape?  I'm looking for something transparent and adhesive, but not so adhesive it can't be repositioned or removed later.

The graphics I have in mind are home-printed "stickers" (but on printer paper, so they don't have adhesive) and registration marks for things like seat and handlebar position and angle.  I'm not up to speed on painting, so that's not an option.

Scotch tape isn't fully transparent and I don't think it's going to last.

Clear packing tape is nice because it's clear but the adhesive can be hard to remove after a while without using things that can damage paint.

The project's coming along.  I'll have a final report after I try some with sticker paper in the printer.

Here's a picture taken when using Gorilla Clear Repair Tape (on seat tube above the FD) and packing tape (below the FD).  For anyone horrified by the condition of the frame, keep in mind this is my beater bike, meant to look not worth stealing.  If it hadn't come this way I'd have had to distress it on purpose.

Sizing tests on the frame and a reminder on the stem, both with Scotch tape.  The one on the stem has been holding for three months.

If you want to use tape, then you want to use what's commonly called "helicopter tape" (or "racing tape" or "repair tape") by car customizers. It looks like transparent packing tape but is much stronger. The story goes that the tape was used to cover the leading edge of helicopter blades to protect them. So it's tough, waterproof, and won't easily peel. And when you do have to peel it off, it comes off relatively cleanly (the remainder cleans up with GooGone or similar removal liquid).

That said, you need to be careful of what you're covering. Even with helicopter tape, some moisture always finds a way of getting underneath into the paper so it should be printed with waterproof ink. And UV light will also fade. So you generally shouldn't just use something that's coming out of your home inkjet printer.


How to service a Shimano TZ rear mech? I'm trying to swap out the top jockey wheel on a rear shifter mechanism.

The bottom jockey wheel simply unbolted as expected but the top one seems to share a shaft with the main spring rather than having its own bolt.

I can twist one of the cage plates a complete turn but it doesn't unthread anything.

I can see a steel nubbin through a small slot, but its not shaped like a bolt head.

Is this Unserviceable?

These units are simply not meant to be serviced. The end of the bolt looks stamped like a rivet anyhow.

It may be a bit short as an answer but it's the (bitter) reality.


Is it normal for the chain to slip in an 'extreme' gear? My bike's recently been in for a service so afterwards I checked that all the gears are shifting and working properly.

As part of my testing I put some power through the cranks in the photographed gear and found that the chain slipped. Having found that out, I tested it some more and it's very easy to get the chain to slip in that gear by putting some power through it.

Is that normal? Could it be the derailleur set up at fault?

I don't ever use this gear day-to-day so it doesn't really matter I suppose. However, I'd like to think that everything was 100% working okay having paid for a service.

Should a service leave a bike in this kind of state? The bike's 11 months old and hasn't been heavily used in that time.

In that extreme cross chain configuration you have the maximum amount of chain for the derailleur to take up.  And you also have the least amount of chain tension.  Combine that with on the least number of teeth engaged and you have the configuration that is most likely to jump.

Should it jump no.

It is a shop problem - maybe.

In just 11 months the spring in the derailleur could have weakened.

Or if you ride on the small gear in the rear even a bit it will wear and new chain might skip.  But given it does not skip on other front gears I would chalk it up to chain tension.

The shop may have too many chain lengths.  In biggest front and rear could a chain length be removed?

Cross chaining a road bike or the first two chain rings is something that happens.  But on a mountain bike in the granny gear that extreme cross chaining is just not something that should come up.  I would not put that kind of stress on a chain even to test.

Some front derailleur have a trim for big to big.  This make sense to me as you may come to a stop but will get back up to speed soon.  And now you have maximum teeth evolved.  I don't know if trims comes in a 3 speed and it would make less sense as the outer is out further.  Even with a trim cross chaining puts more stress on the chain and other components and is not as efficient.

The question is not about specifically about cross chaining but here is a link.
Technical Details and Implications of Cross Chaining

Not the question but the smaller rear gears are going to wear the fastest as they share the load across fewer teeth.  So go for a larger front ring when you have choice. But still avoid cross chaining (a lot).


How to remove axle and bearings from a B'TWIN Triban Aero wheel I have a B'TWIN Triban Aero rear wheel and am trying to replace the sealed bearings. After removing the end caps and a DS rubber seal I can see the ends of the bearings, at this point I assumed that the axle could be removed by tapping with a hammer, however with a reasonable amount of force it didn't move. Do I just need to be more aggressive or is there a further step before the axle and bearings can be removed from the hub?

The assembled hub.

The DS with the bearing seated within the freehub.

NDS bearing and axle.

I can't say 100%, but this looks like the sort of hub where you just need to smack the ends of the axle sufficiently hard to drive the bearings out. Make sure you're bracing the wheel by holding the hub and not the rim.


Getting the hub logo facing the valve hole? I have built a number of wheelsets and always struggle to get the hub logotype "upwards" and faces the valve hole in my rim, so that it aligns with the tire logo.

Instead of getting it right the first time, I end up lacing a whole bunch of spokes and then moving them one at a time until everything looks as intended.

How do I do it?

Place a single leading spoke and a single trailing spoke- both on the same side of the hub- to get your placement correct. That way you only have to unthread two spokes if you're off. Once you've got it right, unthread the leading spoke if you're planning on lacing trailing first or vice versa and proceed as normal with lacing.


Need help with putting together a mountain bike I am thinking about building a new mountain bike but I'm not really sure what I need. I found a used Giant Anthem Advanced Carbon Mountain Bike Frame and I want to put disc brakes and Fox shocks on it. But the problem is I'm not sure what fork to get.
If anyone could help me, that would be great.

Here is the bike.

The first thing to note is that the frame has to fit you. Also, the frame and rear suspension should be known to be in good condition before you buy the frame as well - this is especially important for carbon due to its failure modes.

If you don't have experience with this [and it sounds like you don't, given Fox pretty much makes shocks for everybody], you should probably work on this with a bike shop since the assembly process will require tools you likely don't have (and even if you have the tools, it may require expertise which you might not have, such as how to cut forks to the right length). Local riders can also help you spec a bike which is appropriate for the type of riding you do (for example, full suspension may be unnecessary in your area making this frame a bad choice and certain types of forks may be popular among people in the area for good reason).

Generally, when selecting a fork, you will need to match the headset type and the fork geometry to what the frame is designed for. This question has a nice answer which summarizes those things and as does this link. Obviously, it needs to be able to mount the brakes you want.

As for selecting disc brakes, read some reviews on various models and choose one based on your needs.

In any case, voting to close this question, since it is primarily opinion based, highly dependent on the type of riding you do, your budget and your location.


Technical documentation for Shimano FC-M510 I'm having a hard time finding the technical documentation (equivalent of https://www.dropbox.com/s/yx5hq4cezpdz641/alivio-crankset-service.pdf?dl=0) for the Shimano Deore Hollowtech 1 crankset, FC-M510.

Among others, I'm looking for information about which BB size I should get. Anyone has any info?

That is an older style octalink crankset.  The documentation is available here for the octalink version and here for the square version.  As to what size BB you'll need that will depend on your frame.  There are several sizes of octlink BBs available depending on how your frame was manufactured.  If you don't have your old BB available with a legible size on hand, I would recommend taking the frame and cranks into a shop and having it measured so they can order you the correct size.


How to attach cable mounting points to a bicycle frame? I have a frame-building project that is near completion: An old 90ies steel MTB frame was cut, and converted into a frame for a cargo bike.

In my enthusiasm, I have overlooked one detail: The original routing of the shift cables (shown in the photo below in green) is not possible any more, because

the frontal mounting points near the position of the former head tube were cut off (schematically shown in blue in the attached sketch), and
the cargo beam is attached below the bottom bracket, and therefore takes/blocks the former place of the shift cable guide.

My idea is now to re-route the shift cables along the top tube, as schematically shown in yellow in the photo.

However, I'm still missing the mounting points. If possible, I would like to avoid removing the paint and start welding again. Are there any options, like some cable casing mounting points that can be attached with screws, clamps, or something alike?

Since I believe that this could be interesting to any person that likes to tinker with old bike frames, I'm putting my question here.

I'd go with full housing for both brake and gear cables and hold the cables on with cable clamps. There are many kinds of cable clamps to choose from. I prefer the type that have a screw clamp over the clip on type. The key will be finding clamps for your tubing diameter.

If you need to have cable stops there are clamp on versions from a variety of vendors. problemsolversbike.com has a variety of solutions for tricky problems.

Items linked are examples and not endorsements.


Checking fixie for damage This morning during my morning commute I had an unintended lesson in fixie skidding: I dropped the chain, it got stuck between the cog and the hub and locked the wheel. I'm not sure where that skill came from, but I managed to come to a controlled stop without falling, crashing into the curb, or swerving into traffic. Scary, I must admit.

I was only a few blocks from work, so after a good deal of not-so-gentle pulling I managed to dislodge the chain, get it on the chainring and cog and get going. I did notice during the short remainder of the trip that if I applied back pressure on the pedals, the cog was no longer being held in place by the lockring. Not that I understand how that could have happened, but other than that and the terrible skid mark on the tire, nothing else felt wrong.

Once I get home I will get a new tire on (kids, put brakes on your fixies, if only for financial reasons!), tighten the cog and lockring, check them for damage, measure the chain to see if it needs replacement, and make sure it sits a little more taut.

Am I missing anything? Not sure if I should be looking at anything on the hub, spokes or elsewhere...

Update I spent some time with my back wheel today. The spokes are all dented and scratched, but the wheel is holding up well. I took the lockring and cog off, and they both looked fine, same with the threads. After cleaning them up and putting some grease on the threads, I put the cog back in and tightened it with no problems, but when I was tightening the lockring it disintegrated: it obviously cracked during the chain jam, which allowed it to move out without stripping the threads. I am riding on the flop side of the wheel now, which has made for an interesting discovery of forgotten feelings. I had been thinking of taking a tooth off my back cog for some time, so I'll just go ahead an order the whole pack: cog, lockring and chain.

I would certainly give a lot of attention to the chainring and lockring. One question that I think you need to answer is whether the lockring was loose before the incident or did the chain jamming the cog cause the lockring to come adrift. Then you need to consider whether the lockring loosened naturally, i.e. did it turn along the thread, or was it forced sideways?

Do you tend to use a rear brake? From the question I get the impression you don't. (This isn't a criticism - I don't have a rear brake on my fixed, either.)

If you use back pressure a lot when slowing and the lockring had been a little loose (when was the last time you checked it?) then it might be that that was what helped contribute to the jump - this is probably the best case for you, certainly the case with the least likelihood of damage beyond the tyre's flat spot.

If you're sure that the lockring and cog had been tight before the incident, then I would really give the threads a careful review because you might have stripped them and caused some lateral damage.

Given the jam, I would certainly be looking at the spokes: go round the wheel, both sides, just trying to gently flex each spoke, they should each hold firm; listen for creaks too. It also never hurts to pop the bike in a stand and just run the wheel round a few revolutions and watch its line - even if the spokes are all firm, you might see a little wobble.

And if you're really thorough, go over the chain and check for bent links (and while you're at it, give it a good wipe and a lube, you can't do that enough).


Are there any bluetooth speed sensor with data logging ability? I use my bike mostly for getting around town. First I used smartphone gps apps to record my trips, but I often forgot to start or stop recording. Then I used a bicycle computer, but I didn't like it too, because I had to remove it from the handlebar every time I locked my bike on the street.

The ideal device I am looking for is similar to any bluetooth speed sensor, but can record my speed (or at least total distance) without my phone, has decent battery life, has bluetooth 4.0 connectivity to download recorded data once in a while, and I can leave it on the bike.

I do not need wires, screens, just a small smart sensor, which can record data on its own. Is there anything like that on the market?

I have used cheap bike computers for several years on three different bikes. These are the simplest solution for tracking mileage. I never remove them from the handlebars when I park and none ever got stolen; I don't think they are very attractive to thieves. (If you are worried about theft, note that your fancy Bluetooth-enabled speed sensor might also get stolen...)


Options to reduce reach on a gravel bike I bought a 2020 GT Grade shortly after the pandemic hit. Bought it online, no test drive. It was a bit of a risk, but it seems to fit well enough with one exception: the reach feels a bit long. When I ride the hoods, I feel a little too extended. I'd guess I need to decrease it by ~30 mm.
I'd love to get a real fitting, but understandably none of the shops in my area are doing that yet, so I'm winging it and looking at some options with the help of my LBS.
My initial inclination was to shorten the stem. (It's about 80-100 mm.) But when I talked with my LBS he thought that that might modify the steering too much and suggested instead that I consider "short" or "ergo" drop bars. I think my current bar reach is about 100 mm, and I see some for sale that are 65mm.
So, my question to this great group is what is your opinion on the best way to reduce reach:
1/ shorter stem
2/ change out the drop bars
3/ something else?

When riding on the hoods reducing the reach of bars is equivalent to using a shorter stem. Only when riding on the tops a shorter stem will lead to different steering compared to shorter reach bars.
A change of 2 cm to 3 cm will change steering. However, it is not so dramatic that you will hit the dirt right away. Especially on gravel bikes that typically have slack steering angles and tend to be quite stable.
Swapping a stem is a bit less work than swapping bars. Stems tend to be slightly cheaper as well. Neither is terribly expensive or much work. You might give it a try and see if you like it.
An alternative would be to lower the height of the bars, by moving the stem further down, and/or flipping it down. When you tilt your upper body at the saddle your shoulders move roughly on a circular path. The lower your upper body is the further your shoulder are forward.
Before starting to get your hex keys you might want too try if you feel to stretched out when you are down in the drops, holding the bars where you can brake.


How to tell if a newly built bicycle wheel is safe to ride? I recently finished building my first ever bicycle wheel, and now I'm planning to test ride it. Since this is my first wheel build I want to safely test it to ensure that the wheel won't fail catastrophically while I'm mountain biking or riding in busy traffic. The wheel is both laterally and radially true, dished right, and with spokes that appears to be evenly tensioned. It looks and feels like a real bicycle wheel, in other words. But looks can be deceiving. How do I safely test a new bicycle wheel to get a reasonable assurance that it is safe for heavier useage such as mountain biking?

You said that it is laterally and radially true, dished correctly and properly tensioned. Sounds like its ready to ride! As far as i know there is no real true test method other than riding. I would just take an easy ride around the block or on a tame trail. You may find that after riding for a bit you will need to re-tension some of the spokes after they have settled in. This is pretty normal with use.


How do I install a fixed gear cog on a screw-on freewheel hub? I'm converting my old favorit bicycle to a fixie, but the hub is obviously not made for a fixed gear cog. I've removed the freewheel (not sure if it's called that, the thing that spins backwards on the hub..) but I'm left with a "screw on hub" (the cassette with the freewheel was screwed on to the hub). How can I install a fixed gear cog on that? Is there even a way? please help..

I've not done this, but I beleive the threads are compatible with a standard fixed gear cog. If so, just buy a cog and install it. Then put a lockring from an adjustable bottom bracket on as a lockring (it has the same threads as the hub).

Note that this will not works as well as a proper fixie hub, most obviously because it's missing the left hand threaded section that normally holds the fixie lockring in place. I strongly suggest using locktite, or possibly even superglue, to hold the cog in place. Otherwise when you back pedal to brake there's a real danger that the cog will undo and you'll lose drive.

There's a detailed explanation here that covers what you've done plus the next steps.


V-brake noodle broken: replace immediately? With what? I realized today that the front brake noodle on my folding bike is most likely broken. It looks normal as long as the wheel faces left or forward. As soon as the wheel faces right, however, the noodle gets a weird bend (see pictures).

The brakes are still working, but I suppose I should replace this noodle in the near future. Should I look for something special or are they standard parts? Do I need to replace other parts like the cable?

In addition, I am wondering how I can make the replacement noodle last longer. The big cable tree of the folding bike seems to put quite some pressure on the noodle.

Thanks for your help.
Matthias

A noodle is totally cheap, and you should replace this immediately even if the brake appears to be working.   Dragging the inner around a sharp bend will fray the strands, leading to a sudden failure and a lack of front brake when it snaps.

Noodles come in two different bend radius.

90 degrees, often used on the rear brake
135 degrees, which is most common on the front brake.

Your folding bike might use either, it looks like a 90 degree one to me.

Note, you should change the inner brake cable at the same time.  Depending on condition, its also a good time to replace the outer if anything is wrong with it, like cracks or bends or rust.


difficulty in shifting to lower gear on shimano (6 speed rear gear) I am new to using a bicycle with multiple speeds. I got this new bicycle 4 days back with Shimano 6 speed rear gears. I don't know much else about the components.

There is no issue when I move to higher gear (2 to 3 , 3 to 4 and so on.)

But I face issue when I try to shift gears from 5 to 4 or from 4 to 3 etc. The chain does not shift and it makes a sound.

As a trick to get it to shift into the desired gear, I shift to next higher gear when the chain makes sound and then get back to desired gear. e.g. if I am riding in 5th gear and I want to shift to 4th I shift to 3rd for a moment and get back to 4th and then all's well with no more sound from chain. But I am afraid this trick may not be good and that I may be doing something wrong.

So I request guys to suggest me proper way to shift to lower gears.

I tried to find videos on youtube but they didn't help much. The videos show shifting should not be done while pedaling under pressure, so I followed this but shifting was still not smooth.

There is a problem with the cable that links the shifter to the mechanism (rear derailleur)

The cable has become slack over time and needs to be tighter. You can tighten it by turning a barrel adjuster if there is one present. it might be as pictured and there might be one where the cable leaves the shifter on the handlebar. looking in the direction of the arrow, turn the barrel adjuster anti-clockwise to make the cable tighter.

Make small adjustments, ie one quarter turn at a time. You could search for videos to help. It's straightforward when you know how, but difficult and frustrating the first time. Your local bike shop would be happy to help you too.


Can I convert a 1x9 speed Madsen kg271 cargo bike to a 2 or 3 x 9? I know most these days seem to want to go the other direction, but my partner would like more gears on this heavy cargo bike that can be tough to pedal uphill.  I think the frame has all of the necessary cable stops etc. for installing a front derailleur. And I know it would have to lose the chain guard.

But, I don't know much more than that. Like, is it possible to change the crankset to a 2 or 3 ring version? What else would have to be changed? What has to be compatible, and how do I make sure that it is?

I am pretty handy, and might consider doing at least some of the work myself if I can, and if it's even possible, but I don't know how to make sure it will all work together.  And, if I can pick up components as I find good deals on them, that would be great too, so I need to know what to look for and what has to match, even if I'm going to have someone else put it all together.

I will do my best to provide additional information if it is needed. Thanks!

This link says the frame has the necessary cable stops for a front shifter and front derailleur.

You'll need a new crankset (you can find 9 speed+ triples or doubles pretty cheap these days). This may require a new bottom bracket as well, depending on which crankset you choose (I'd guess whats on there is just standard square taper) and the chainline required.

You'll also need a front derailleur. Front derailleurs come with a slew of selection criteria: top/bottom/dual/side swing pull (the cable comes from the top/bottom/top or bottom/ side), where the derailleur is mounted (top swing (the derailleur swings above the clamp), bottom swing, direct mount/e-type variations, braze on, band clamp) and if its designed for a double or triple crankset. Then, you need the derailleur to have the appropriate chainring size constraints. There's a good overview here of types of front derailleurs. The mount type necessary is dictated by your frame.

You'll also need compatible shifters (I'd suggest buying a front shifter from the same manufacturer and mountain/road type; They get a bit weird with these 11 speed-intended FD's though).

As mattnz pointed out in the comments (thanks!), you may also need a new rear derailleur (which has to be compatible with your shifter), in order to have the capacity for the chain in the new chainrings.

I'd suggest heading to your bike shop, and having them determine what kind of FD goes with your frame at the least. You'll need a few specialty tools for this -- bicycle cable cutters, a crank puller and possibly a bottom bracket tool.


How to select bottom bracket spindle width? I'm trying to rebuild a bike that I got given free of charge. The bike had no bottom bracket in when it was given to me. How do can I select the optimal spindle width please? I know it's 68mm shell.

Edit: I don't have a local bike shop nearby so I can't take it to one as per suggestions in a previous thread.

Edit: http://www.chainreactioncycles.com/shimano-un55-square-taper-bottom-bracket/rp-prod71369 is the bottom bracket that I need. English thread, 68mm x Y. Unfortunately I'm unsure of what Y should be. By the look of Sheldon Brown I need 47.5mm from the middle chain ring from the centre of the seat post (measuring to that sort of accuracy could be fun). This is where I'm baffled. I could order a sacrificial bottom bracket to measure what size I need by seeing how far out of 47.5mm I am. Is that what I'm going to have to do?

Edit: I do have a crack. It was a spare one I had left over from a few years ago. It's a triple chainset one by SRAM called Truvativ Isoflow.

You will have an easier time selecting the correct spindle once you have already selected a bottom bracket, because the spindle size is typically specific to each bottom bracket. Once you have the bottom bracket, you should be able to nail down the spindle size either from the manufacturer's instructions or on Sheldon Brown's database:

http://www.sheldonbrown.com/bbsize.html


How will swapping drop bars to butterfly bars affect bike fit? I recently bought a Dawes Super Galaxy from the late 80s or early 90s. When I was researching bike fit beforehand I was told that swapping drop bars to flat bars can affect the bike fit since drop bar bikes are designed bearing in mind that hand position is further forward.
The bike came with flat bars which the previous owner had fitted and they're not that comfortable. Since I want to try touring I'm looking to fit handlebars which provide multiple hand positions, but I'd also like to maintain a more upright posture for commuting.
Will fitting butterfly bars return the bike fit more to what the manufacturer intended with drop bars?

Not really. The rear position on butterfly bars is about like riding on the tops with drop bars (or riding on flat bars), and that seems to be the "default" position, as that's where the controls are mounted. The outboard position is a bit like the ramps on drop bars, although higher up and much wider--road bars are rarely more than 440 mm wide, butterfly bars are more like 580 mm wide--in order to have the same reach in this position, you might want a shorter stem. Drop bars don't really have an equivalent to the forward position.
There's nothing wrong with using trekking bars, but I think you need to evaluate them on their own merits, rather than as an approximation of drop bars.
Drop bars these days tend to have a much shallower drop than when that bike was built, and I'm guessing that bike has a quill stem, which means it's easy to raise and lower. You might be able to get a relatively upright position even with drop bars.


what make and model is this bike please? Please help me identify this bike, I have looked in a
multitude of places and come up with nothing.
It looks to be a beach cruiser.

This bicycle is a Micargi Mustang.

See this Google search.

An an image from this website:


New high quality tire doesn't sit evenly on the rim It's my first tire change experience and I got so far using youtube videos but now I'm stuck.
Got these Schwalbe 365 tires yesterday for my folding bike.
It is an all season model which feels a bit harder than the tire that was on the bike from the factory but both are 40-406 20x1.5".
The bead doesn't sit properly on the rim. This is the case from both sides as seen in the images. There's a small misalignment between where the problem manifests itself on each side of the rim.
The tube is also brand new (Continental). The temprature in the bicycle room where I tried is around 16-22 deg.

Hadn't used soapy water when installing the tire and can't measure tire pressure (it's recommended 3-6 bar).

What do you recommend to solve the issue?

Update: bought a pump with gauge, rotated the tire and used a bit of liquid soap to end up with this result:

One thing that I discovered today is that the tire is literally tighter at the point where there's a problem which makes me think the tire might have some issues due to how it was stored I  the shop. But that would be too sad because despite the issues I really like these tires.

The tire sidewall is just hung up on the rim a little. It’s a common problem.

Deflate the tire until you can deform it a little with your hands, rotate the wheel so the problematic section is at the top. Grab the tire from the side and lever it back and forth. You should be able to pop it out so the bead sits on the rim properly.

BTW, a pressure gauge is a good investment so you know you are inflating your tire to the proper pressure.

Here's a link to Park Tool's video on tire installation, at the point it addresses the bead being too high or low.

            .


Should I change the tire and tube or can it be patched? Someone deliberately pierced the rear tire of my fixed gear bike. It's a 700cX25 tire with 700cX18-23 tube inside. As you can see from the image the threads have come out. I am not sure about the severity of the damage. So what should I do of the following remedies:
1. Replace both tire and tube
2. Replace the tube and patch the tire
3. Replace the tube and leave the tire as it is
4. Patch both tire and tube

What can you afford?  If you're not really struggling financially you should replace the tire.

If you cannot afford that (or if you need a temporary fix while you're obtaining a new tire) then you need a "boot" inside the tire.  A "boot" is some piece of flat material (typically about 5 cm x 5 cm, though size can vary based on tire size) that is flexible but still stiff enough to resist the pressure of the tube trying to poke through the tire.  You can buy purpose-made boots made from plastic or rubber, you can cut your own boots out the (thin) sidewall of an old road tire, or, popular in the US, you can fold a dollar bill up several times and use that.

The boot is used by inserting it into the tire after the tire is mounted and the tube is in place.  Pry the tire off the rim near the hole and slide the boot in between the tube and the hole.

Using a boot is not as reliable as replacing the tire, of course.  There is a danger that the boot may shift over time, especially if the tire pressure is not properly maintained.  And a boot is an even less reliable fix for a hole in the sidewall of a tire.

The tube is actually less of a worry than the tire.  If the hole is a puncture rather than a cut/slit, or it's a very short slit, then you can patch it with conventional tire patches.  If the cut is so large that a standard bike patch will not comfortably cover it (with maybe a 10mm margin) then the tube needs to be replaced.


Bicycles riding in pedestrian crosswalks -- Houston Should cyclists ride (not walk) their bike through a pedestrian walkway at an intersection?  This may vary by municipality, so I am specifically interested in Houston, although I would be curious about other cities as well.

I've had several close calls as a driver with bikes coming out of nowhere rapidly on the sidewalk and crossing while I was making a turn.

I suspect that the answer here would be to use some common sense.

I'm not sure anyone would condone cyclists riding along the pavement/sidewalk - intersection or not. This is a risk to pedestrians, and generally gives cyclists a bad reputation.

But, as a motorist, what are you going to do? Drive into them?

I'm pretty sure that in most any jurisdiction, that would put you in the wrong.

Even if you did so accidentally, when you had right of way, I'm pretty sure you'd find yourself in a position where you'd have to prove your innocence, rather than someone having to prove your guilt.

Driving is a social activity in that, like it or not, we have to share the roads with other people. Try not to let the fact that some of those people (whether on 2- or 4-wheels) are idiots, ruin your day.


Can I use a Shimano XT 11-gear derailleur with a 10 ring cassette on a mountainbike? I put a 40-11T 10-gear cassette on my mountainbike, but did not check whether it was compatible with my current xt shadow+ derailleur. Now the derailleur rubs against the cassette in higher gears. In the future I would like to put on an 11-gear cassette.
So that I don't have to buy a new derailleur now and then again in a year or so I would like to install a derailleur that will work with both.
Is this possible?
Thanks

10 and 11 speed systems are not compatible. The pull ratio of the shifters is different, as is the cog spacing of the clusters.

You may get away with some combinations of frankien-mixandmatch, but as the drive chain wears, the differences become more problematic. Ultimately, most find its not worth the problems it creates.


Is the banjo bolt the same between the Shimano XTR and Shimano Saint rear brake caliper? Earlier today, I went to install a brand new Shimano Saint caliper in place of an old XTR that's leaking from the pistons, only to find that Shimano doesn't include the banjo bolt...
Do the XTR and Saints use the same banjo bolt?
Is there anything else you need to do the swap that I might be missing?

edit: The only XTR calipers that used the appropriate banjo bolt for your Saint brake were part of the m960 series, which was released in the early 2000s and had integrated brake/shift controls (push the brake lever sideways to pull shift cable). these levers used the BH96 hose, which is equivalent stiffness to BH-59 and also had a banjo fitting at the lever. Unless you shift by pushing the brake lever, you need a new banjo bolt.
The only banjo bolts compatible with the BR-M820 are the short banjo bolt (with the o-rings, this is part number  Y8H098010. the bolt by itself is  Y8H001500, and the o-rings are  Y8SY28000) or the BR-M8100 spec bolt (Y2RT98010 and  Y2RT05000, respectively). This is from the Shimano compatibility table on "Compatibility between banjo bolt," here. Your bike shop may have a Shimano hydraulic brake small parts kit kicking around, with a few of these in a plastic container with a bunch of dividers and other things like rotor fixing bolts, retaining washers, and IS caliper mounting shims. Neither of the compatible banjo bolts are compatible with any of the current XTR calipers; the bolts used on those calipers are all too long. both M-810 and M-820 Saint calipers used the same banjo bolt, and it is not used on any XTR caliper with banjo fitting for which I could find an exploded view on si.shimano.com, except for the early 2000s  BR-M965 (IS mount)/BR-M966 (post mount).
The caliper is compatible with standard length banjos (not banjo bolts), but be advised that for heat dissipation and to put more distance between the hose and the hot part of the caliper, Shimano's gravity oriented brakes like Saint usually come with hoses fitted with a long banjo. You can use any banjo-equipped BH-90 hose, but it needs the short banjo bolt. your existing hose and banjo will fit, but consider a new hose kit with the long banjo depending on your riding/braking style.
If you're buying a new hose kit, here's a screencap of the 2021 Shimano genuine parts catalog with the parts numbers for all hose kits that come with the appropriate banjo bolt, because there are many options and availability may vary. Or you can try and get the banjo bolt separately, as above.

On the last part of your question, just to cover the bases:
-Always use genuine Shimano mineral oil, or for other manufacturers' mineral oil brakes, the brake fluid recommended by the brake manufacturer; third party mineral oil brake fluids can and will damage the seals, because mineral oil fluids are not all chemically the same, regardless of viscosity- the tolerances on seals and bladders are tight and Magura or other fluids can cause the seals to swell.
-Follow the service instructions at si.shimano.com, use a torque wrench, and a dedicated bleed kit for Shimano hydraulic brakes- don't use the same bleed kit for different hydraulic systems, like those that use DOT fluid. si.shimano.com is a great resource for Shimano products, and I encourage anybody working on their own Shimano-equipped bikes to familiarize themselves with this resource.
-When bleeding a used brake, start with a gravity bleed to avoid pushing dirty fluid up through the lever. There is also a procedure to expose and clean the pistons, one piston at a time, using a modified bleed block.


Flat land speed development I guess I'll start off by saying that I am not a necessarily experienced rider. After years of doing ultra-marathon running I decided to move to triathlon to cross train.  I signed up for a 70.3 a few weeks before it started and turns out I had a knack for triathlon in the swimming(34mins) and running(1hr 40min) section! However, the biking was alright.

I've been training under the guidance of a professional Ironman athlete which has been a world of help(I am training anywhere from 25-29hrs per week). Where we live there is nothing but mountains and rolling hills. Finding a flat area is nearly impossible. I have 3 70.3's which are all flat and fast tt coming up and 2 fulls after which are hilly so no big deal.

I want to know what benefits I gain from training in such mountainous terrain that will transition on the bike on very flat courses.

You have a specific training question that your coach ought to be able to answer for you, and I will not address that here. A larger general issue is one that I will address, since it is of wider interest.

Your general concern is that you won't be able to simulate race conditions in training, especially long steady output. However, speed is determined by power and drag and you can work on each piece even where you are. A rising tide lifts all boats so the power developed while climbing hills and during intervals will mostly be transferable to longer steadier output, especially if that output is substantially below functional threshold power (as it will be for most half- or full-IM efforts). Similarly, you can work on positioning to minimize drag, on your bike handling in rolling terrain (unless the slopes are too steep and the roads too technical), and changes to minimize rolling resistance.

So, the general answer to your general question is that one can separately evaluate and train the components that make one go fast even if training conditions are different from racing conditions. It just takes a way to measure and evaluate progress in the separate pieces, so you can "translate" variable terrain performance to flat terrain performance.

In your particular situation, look toward the bottom of this bike.SE answer to see an example of time splits for an IM. Your swim and run times put you closer to the front of the pack than the middle, but you have lots of room to improve in your bike split. Your run and swim splits suggest that low power isn't your particular issue -- though you can always work on more. Your bike split time suggests that aero drag is likely to be your issue. Your coach can help you work on aero drag even on uneven terrain. To measure and evaluate improvements both in power and in drag may require some additional instrumentation.


How can I remove the bottom bracket from this old road bike? I need some help removing this bottom bracket. I am obviously no mechanic, and watching several videos on youtube I found nothing that could help in this specific case. Basically after removing both crank arms, I take off a plastic cup like dirt protection, and then I see this:

So after turning, looking, sniffing, pushing and tugging - I remove the strange black ring (comes of easily) and I see the bearing cage, however still cannot pull anything out..

Here is a pic:

Anybody recognize this type of bracket? I must get it off because it desperately need cleaning and regreasing.

This type of bearing is not serviceable. The plastic piece is the seal that retains the grease and keeps water and dirt out. The crank needs to be pressed out to remove the bearings. Try to tap the crank with a soft faced hammer. the bearing on the opposite side should be pushed out by the crank. Installing the new bearings will require some care. I have had good success using standard and deep sockets to drive in the new bearings.


Which country has the cheapest top-end mountain bikes? I'm living in Brazil where top-end mountain bikes are very expensive, due to high import tariffs. I'd like to know which country has the cheapest top-end mountain bikes? top-end would mean a bike which can handle a race and is light, not necessarily carbon-fiber.

The factories that make these bikes are mostly in China and Taiwan, I've been told (by my boss when I worked in a bicycle shop).

If you're going there, maybe you can find a nearby retail outlet.


Oval carbon saddle rails compatibility I have a new saddle and I want to buy a compatible seatpost. The saddle rails is CARBON 7x9 as specified by the manifacturer.

I want to understand better the compatibility of this kind of oval rails. Some seatpost manifacturers specify compatibility, here is an example:

  Rail Compatibility    Round and Square Rails

from http://www.zipp.com/seatposts/sl-speed-seatpost--0-/

However, in most other cases, the compatibility is not specified.

Should I assume 7x9 is compatible by default with any seatpost or not?

Edit Follow-up Note: I happened to notice that some manifacturers offer the options of clamps for different size of rails, this is from the Thomson page, for example:

This seems to suggest that there is some difference between the clamps I have to pick.

7x9 is the size that tends to be used when they're trying to make it compatible with "any" seatpost. Normal metal rails are 7mm, so making it a 9mm oval/rounded rectangle fits in in most cases. It's kind of a hack solution that's become normalized. If you look you could find seatposts where a 7x9 will give either iffy thread engagement or interference/awkwardness with the clamp, although neither are common issues by any means. And of course posts exist that clamp the sides of the rails, and you need to avoid those. What you do want to look for is a post that's got nice abundant contact area with the rails and isn't going to press on them with any sharp edges. You can find posts that are counterexamples of this, mostly older basic ones, and thats what you want to avoid.


39-53t chainring on full suspension bike I have a Giant Reign x1 bike which has 2X factory installed 22-36t 4 bolt Sram Truvativ chainring. The question is, is it possible to find 39-53t 4 bolt chainring that can be fitted to this bike  or if it's not possible what tooth ratios are possible?????

The reason I want to increase tooth ratio is my bike doesn't go fast enough on downhills no matter how fast I keep pedaling but in the same trail with my hardtail 3X chainring bike I can gain speed much better.

The highest speed record on trail, downhill, with full suspension bike: 61km/h (it's not possible to go faster unless the hill is steep slope) and with my hardtail one: 74km/h (It was possible to go faster)

The Giant Reign is a long travel 'enduro' bike that is designed to be ridden down steep technical trails, not pedalled down road/fire trail.

It's most likely that changing to a 39-53 will not work as the inner chainring will catch the chain stays, and even if it did work, it would compromise the bike in technical terrain, increasing the chances of 'grounding' the big ring on rocks etc.  You would also probably run into problems with the front derailleur as mtb derailleurs are not designed to work with such large rings, and the frame itself may not allow the derailleur to be mounted high enough to clear the 53t ring.

In addition, it would basically turn the bike into an 'uplift' only bike, as a 39t chainring would be much too large a gear for climbing off-road terrain.


What's best engine to motorize a road bike I have a road bike I use for commuting and I'm about to move 20km further out, so I'm considering fitting a tiny engine to it to assist my ride to work.
However, where I live I have a restriction - the maximum power allowed is 200 watts (about 1/4 HP).
I've seen some kits, but they have huge engines (beats me why they have to be so big).
Further, I'd prefer a diesel engine (no spark/glow plugs) and better economy.
Some brief research has shown that a tiny (5cc or so) diesel engine should be able to produce about 200 watts. A larger one could be de-tuned. There are model aircraft diesel engines of this size, but they're quite expensive.
I've been told a "brushcutter motor" (small two-stroke) could be an option, but they are noisy, smoky and smelly.
I'm not worried about how to deliver the power to the wheel - I'm trying to pick the power plant first then make it work.
Has anyone got any suggestions for:

diesel engine
very small (200 watts max)
not expensive

Edit:
My bike is a Focus Planet TR 2.0 (2012), which has internal hub gears, so the solution can't involve replacing the rear hub. It also has disk brakes front and back, so replacing the front hub may be problematic (not sure).
Regarding range, I will live about 30km away from my CBD and batteries seems to have about a 60km range. Also, recharging takes a while, but filling a tiny tank takes seconds.
Also, I seriously doubt that the pollution created by a tiny 1cc engine exceeds that pollution created by the recharging process of burning coal and pushing the electricity through all the transformers and switches between the power station turbines and a bike battery.
For these reasons, I'm still seeking an internal combustion solution.

There are some bike hubs containing an electrical motor inside. If you google "bike hub motor" and take a look at the images, you'll get the idea.

I think these ones are ideal since they require minimal changes to the overall bike structure, allowing for normal riding if the motor is not working, and they don't burn evil oil: you just plug the bike to the wall and that's it.

The spoked ones should be adequate for building a front wheel with a regular road bike rim.

Hope this helps


Can you help me identify this old bike? I've had this for about a year.  The former owner said he thought it's German (possibly former DDR).  Looks 1950s era to me, but hard to say.  Only identifier is the brand 'Elite'.  I can post more pics if anyone thinks they could ID it.

I can find no information about this marque, other than that there was a former East German bicycle concern called Elite-Diamant-Werke AG.  However, all their bikes were branded 'Diamant' and I can find no evidence that they branded any 'Elite'.

Any insight appreciated.

Here are a couple more photos:

The bottom bracket has a grease nipple, a practice which I believe ended in the early 1960s.  The bearing itself is marked 'BSA' (Birmingham Small Arms), but is possibly not original.

the BSA 1.37" on the BB lockring is for British Standard (association?) more commonly noted as BSC, for British Standard Cycle.  I know these can be swapped out, but looking at the grip shifter and Nexus rear hub, those were early 80's-current, the crank is made to look like a cottered crank, but it's cotterless.  I'm going to say this is more modern than it's pretending to be, grease nipple notwithstanding.  I don't personally know the last time Brooks made that "hat pin" seat...  Just some reference points to look at.


What makes one bike faster than another when same wattage is applied? I have two bikes.  One is a $7k+ Cervelo S-Series, and the other is a <$1K Trek Domane AL 2.  With the same perceived effort applied, my Cervelo goes much faster.  I am able to routinely hit above 20mph mark with ease, whereas with the Trek, I struggle even to get up to 17/18mph.  The Trek is noticeably more difficult to ride.  I feel like I need to apply so much more effot to the pedals in order to get the bike to move.  I would like to upgrade the Trek so that for any given wattage, it goes faster.
My question is, what exactly is making the Trek so much slower than the Cervelo?  A few things come to mind.

Aerodynamics
Weight
Rolling resistance.

The Cervelo is more aerodynamic, but it doesn't seem like the resistance I feel is because of aerodynamics.
The Cervelo is lighter, but only by 3.5 lbs.  Again, doesn't seem to be the biggest culprit.
I have Continentall GP 5000 tires on the Cervelo, and just the stock basic Bontrager tires on the Trek, so that could be part of it?
For me, it seems like the Shimano Claris groupset is the biggest culprit.  It feels very clunky.  Would upgrading to a Shimano 105 be something to consider for this bike?

Most likely aerodynamics.  Modern road bike vendors spend a lot of money improving the aerodynamics, especially for the racing top models. Mor for the so-called aerobikes, but even for the ultra=light bikes, up to the point the weight permits.
The weight is not too important on the flats and is less important than many think even in the hills as most of the weight is in the rider anyway.
Tyres will make some of the difference too. Obviously, top ricing tyres will be faster on smooth tarmac. I made a big improvement from the stock Schwalbe tyres to better G-Ones on my gravelbike. But aerodynamics of modern bikes cannot be beaten by tyres, the differences are usually smaller there.
The groupset may be more clumsy when shifting but when the gear is there, it does it job very well. If you want more gears and have the money (which you probably have if you have the Cervélo S), you can buy 105, it will be lighter, but do not expect to be any faster on flats. (I ride Claris regularly. Some would miss the gears, the shifting requires some power in your hands, but otherwise it does the job done well enough.)


What is this blue mesh tube thing in the Rema TT 06 patch kit used for? I own an (old-ish) Rema TT 06 patch kit. The contents look like this:

Notice the blue tube-like thing under the left box. In the part list on the manufacturer's site, I couldn't find any mention of that thing (http://www.rematiptop.com/part.php?pid=56&cid=5&sid=4, which is also the source of the image).

Is is basically a short tube of mesh-like, flexible material. What is it used for?

Looking at manufacturers site I found repair kit with 'mysterious' blue mesh listed as "Cartridge freeze protector".

It is supposed to be put over the cartridge (like in this picture) to prevent skin irritation/burn because CO2 gets very cold when discharged.


Mongoose Right Bike Gears shifting up magically On the right, or back gears of my mongoose bicycle, the gears are not clicking as they should on the right side. Its stuck in 6th or 7th gear and it has a grip-shift that works fine on the left side. When I try to shift down I can hold it down and it will stay in gear but when I let go it flies back up to 6th gear. How can I fix this?

It sounds like you have a broken or worn shifter. Grip shifters have small plastic teeth inside them. The teeth loosely mesh so that it will move when twisted but tight enough to maintain the selected gear. These shifters are still common and relatively inexpensive generally around $10 US.


Tiagra rear derailleur and Deore crankset + derailleur compatibility I want to buy this bike:

http://en.author.eu/adventure/gravel-bike/author-ronin-2018-ua42901301-1154

For most time, I will be fine with the lowest gear being 34x34. However, occasionally I would like to use it for bikepacking. I used to do all my bikepacking trips with my mountain bike with the lowest gears 20 - front x 32 - rear and I always used this lowest gear on long climbs.

Will the shifting work fine, if I put mountain bike crankset and front derailleur instead of the Tiagra shifter and compact crankset? I want to know, whether I can modify the bike for these occasional trips and if having a spare crankset + derailleur is enough.

You problem comes with bottom bracket width and very likely chainline. The Author Ronin has a 68mm BB shell. With the Tiagra crank it uses a 'Road' type Hollowtech external bearing BB. If you fitted a Deore crank, which has a longer axle, you would need a 'Mountain' type Hollowtech BB with spacers. Without checking I don't know if the Deore crank has a wider chainline, but I suspect it does.

I think you are right you would need a MTB front derailleur, as the rings would be further outboard, but I strongly suspect there is a difference in actuation ratios between Shimano road and mountain front derailleurs which means the derailleur would not be compatible with the Tiagra road shifter.

With all the Road/MTB compatibility headaches,  I'd look at options for getting a lower gear ratio with a road crank. The popularity of gravel riding and adventure bike packing on drop bar road style bikes has spawned several 'sub-compact' cranksets. FSA currently makes a 46/30 crank which would get you under 1:1 with the 11-34 cassette.


What is the proper etiquette for overtaking a horse? What are the general rules when encountering a mounted rider (on a horse) on a trail? I understand if we are approaching each other I would dismount, move to the side of the trail and allow them to pass. However if we are traveling in the same direction and I am overtaking them (say going down hill) how would you alert the rider and not startle the horse? I have not yet come upon a rider on my regular trails but I have noticed an increase in road "apples", so I know it is inevitable.I have heard that dismounting is important as the horse may not recognize you as a person due to the unusal movement(from the horses perspective).

Passing a horse, mounted or otherwise, should be done so:

very slowly
as quiet as possible.  If you have a loud freehub, pedal slowly -- do your best not to coast.
with as much space & consideration as possible
no sudden movements
limit the number of cyclists going past

It all depends on the horses' temperament.  Some are OK, some like cars but not bicycles...
Generally, horses with kids/teenagers riding them on the road will be pretty laid back.  The horses that are being led by someone are much more suspect.

Competent equestrian owners/staff know that any horse [that will be taken or ridden on roads] needs to be exposed very carefully (for the safety of the horse, the rider, and the general public).  They have to accept that the horse may never be comfortable in that setting.  But anything could spook the most experienced horse - you never know 100%.

If possible, send a single person ahead to talk to who has control of the horse while watching how the horse reacts.


Are MIPS helmets actually any safer than standard helmets? Independent Research? A friend just told me about a relatively new bike helmet technology that reduces torsion (rotational) stress in a bike accident. My wife is a speech therapist (and I write speech therapy software) so I'm well aware that tearing is more damaging than concussive forces.

It's called MIPS: Multi-directional Impact Protection System.

But, I'm not convinced the MIPS system actually improves on that. The only independent research I've seen a citation to is in swedish.
And the next best research was on motorcycle helmets

Summary

Research into brain injuries has been ongoing, but tended to focus more on direct impacts. In the last 70 years there has been more research into rotational brain injuries, and in the 1990s and 2000s scientific, evidence based proposals were made to reduce these. The Multi-Directional Impact Protection System is an implementation of these, and it's effectiveness has been validated by independent research.

Discussion

There is lots of research into brain injury. While much of it has focused on direct impact leading to scull fracture, the effects of sudden head rotation have been studied since the 1940s. These (pay-walled papers) are typical

A study on rotational brain injury (1984).
Physical model simulations of brain injury in the primate (1990).

Such studies progressed to proposals, such as

A proposed tolerance criterion for diffuse axonal injury in man (1992).
KINEMATIC ROTATIONAL BRAIN INJURY CRITERION (BRIC) (2011).

  [In] 2008 ... Swedish neurosurgeon Hans Von Holst, along with mechanical engineer Peter Halldin, developed a new technology called MIPS (Multi-Directional Impact Protection System).

A couple of (non independent) articles are

New Helmet Technology Reduces Brain Injury
MIPS

Mips has been received with acclaim

Precious Protection (2010).
Senseless: An In-Depth Look at the State of Bicycling Helmet Technology (2014).

There has been at least one study of their effectiveness

Angular Impact Mitigation system for bicycle helmets to reduce head acceleration and risk of traumatic brain injury. (2013).
This found a 34% reduction in peak angular acceleration and predicts that AIM helmets reduced the risk of concussion [by] 44%.

But not everyone is convinced regarding helmet effectiveness. For a helmet skeptic's view see

Cycle helmets and rotational injuries.
The views expressed here are out of date, but it's the only skeptical view I found regarding rotational brain injuries.

Certainly, more independent validation would be good, and in future better designs could appear. At present MIPS seems to set the brain protection benchmark.


Drivetrain wear -- questions on chain elongation and skipping Pitch (i.e. the distance between two links/two cogs) is a major issue in drivetrain wear, which explains why waiting too long to replace a chain may lead to premature cassette replacement.

This being said, three questions:

1) What is the maximum chain elongation tolerated by a new cassette? 1.5%? 3%? Can you explain in some amount of detail? (intuitively I would think that the answer involves taking into account the difference in sprockets' radius at the bottom and near the top of a cog -- as chain pitch increases, it rides higher and higher on the cogs, up to the point where it is no longer gripped by the cog).

2) What is the maximum chain elongation at which a chain will skip on sprockets that have not been changed during the life of the chain? (intuitively I would think that the answer would be the same as above, or a tad lower - worn sprockets have deformed cogs, but the same principles apply).

3) Large sprockets last longer than smaller ones. Why? (intuitively I would think that wear is a function of the number of revolutions -- or distance/speed)

According to Park Tools:

  A worn chain shifts poorly and wears sprockets at an accelerated rate.
  The CC-3.2 is a go/no-go gauge designed to accurately indicate when a
  chain reaches .5% and .75%, the points at which most chain
  manufacturers suggest replacement. For 9 and 10-speed chains, replace
  chain just as the gauge fits the 0.75% side fits flat into the chain.
  For 11 and 12-speed chain, replace as the 0.5% side fits. The CC-3.2
  is long, accurate and features permanent measurement markings.

The 0.5% - 0.75% answers when you should replace the chain but does not answer the max stretch before skipping.

Sheldon Brown's site ( http://www.sheldonbrown.com/brandt/chain-care.html ) indicates things get dramatically worse once the elongation reaches 1.0% because at that point it is every other link that is load bearing... so I would assume >= 1.0% is the answer with the variance being attributed to the condition of the cog.  Checkout the link and you will learn more than you can imaging on chain-cog engagement.

  The best way to determine whether a chain is worn is by measuring its length. A new half inch pitch chain will have a pin at exactly every
  half inch. As the pins and sleeves wear, this spacing increases,
  concentrating more load on the last tooth of engagement as the chain
  rolls off the sprocket, thus changing the tooth profile. When chain
  pitch grows over one half percent, it is time for a new chain. At one
  percent, sprocket wear progresses rapidly because this length change
  occurs only between pin and sleeve so that it is concentrated on every
  second pitch; the pitch of the inner link containing the rollers
  remaining constant.