What is the mechanical advantage of mechanical rim brakes and levers? I understand that the amount of hand force required for a given braking force
depends on the mechanical advantage of the braking system, which in turn is
a multiplication of the mechanical advantage of the levers and the mechanical
advantage of the brakes.
However, I have not seen any definitive resource on the mechanical advantage
of the brake components. How can the mechanical advantages be determined?
Let's limit this question to rim brakes. Disc brakes can have their own question.

Levers:
Here calculating the mechanical advantage is easy. It is the distance from
pivot to fingers divided by the distance from pivot to cable anchor.
Examples for levers:

Dia Compe 287V V-brake drop bar levers: 75mm / 29mm = 2.6x (approximately)
Tektro RL520 V-brake drop bar levers: 72mm / 33mm = 2.2x (approximately)
Shimano BL-R400 drop bar levers: 72mm / 14mm = 5.1x (approximately)
Some cheap Shimano V brake flat bar levers: 60mm / 38mm = 1.6x (approximately)

Note that the mechanical advantage of drop bar levers depends on where your
fingers lie on the lever. The mechanical advantages here were for braking on
the drops. On the hoods the fingers cannot reach as far down on the lever, so
with my hands, the numerator of the division is only 63mm. Then the mechanical
advantage of Dia Compe levers drops to 2.2x, Tektro RL520 levers drops to 1.9x and of BL-R400 drops to 4.5x, but
of course it needs to be remembered that the fingers are in an inoptimal angle on the
hoods, so the brakes feel even worse than what you could assume solely based on the
theoretical mechanical advantage. On flat bar levers there is only one braking position.
Brakes:
For single pivot sidepulls, the mechanical advantage can be calculated by
dividing the horizontal pivot-to-anchor distance by vertical pivot-to-shoe
distance. I do not have any single pivot sidepulls here, but if I search for
pictures of old Campagnolo Record single pivot sidepulls, their mechanical
advantage seems to be around 1.0x.
Sorry I don't have any dual pivot sidepulls here and I cannot analyze their
complicated mechanism without seeing the brake in real life as opposed
to seeing it only in pictures on the Internet. Thus, I cannot
analyze the mechanical advantage of dual pivot sidepulls. Presumably
it is higher, but how much higher I cannot say. Feel free to edit
this answer or to provide another answer for dual pivot sidepulls.
I saw detailed enough pictures of dual pivot sidepulls here: https://www.parktool.com/blog/repair-help/dual-pivot-brake-service -- from picture in "6 CENTERING" I estimated (using pixel-level measuring tool of Gimp) that the less forceful arm has a mechanical advantage of 269.3/278 = 0.969x and the more forceful arm has a mechanical advantage of 444/206 = 2.155x. Because there is a forced centering mechanism, the average mechanical advantage is about 1.6x and it applies to both arms of the brake due to the forced centering mechanism.
Cantilever mechanical advantage calculation is a bit tricky. I have developed
software for calculating mechanical advantage of Shimano BR-R550 cantilevers on
Surly Long Haul Trucker 28" frame, where the vertical pivot-to-shoe distance is
31mm. On this frame, the Shimano Link Wire "E" gives a mechanical advantage of
1.5x. The Shimano Link Wire "F" gives slightly lower mechanical advantage.  A
benefit of cantilevers is that their mechanical advantage can be adjusted by
adjusting the straddle cable length (old brakes having the somewhat dangerous
straddle cable that can lock the brakes by dropping to a knobby tyre) or by
switching the link wire to one of different length (new brakes). A drawback of
cantilevers is that the mechanical advantage reduces when pads wear,
and is actually reduced as the pads move closer to the rim, so
mechanical advantage during free motion is high (bad as it means
low pad clearance) and mechanical advantage when pads have reached the
rim is lower (bad as it means low braking force).
There is an existing resource of cantilever geometry by Sheldon Brown but I believe it has a fatal
error in the mechanical advantage formulas: it uses the direct pivot-to-shoe distance
as opposed to the vertical pivot-to-shoe distance. Thus, it gives too low mechanical
advantages as the direct pivot-to-shoe distance is always longer than the vertical
pivot-to-shoe distance.
V brake mechanical advantage calculation is easy: divide the vertical
pivot-to-anchor distance by the vertical pivot-to-shoe distance.
Example on Surly Long Haul Trucker 28" frame having 31mm vertical pivot-to-shoe
distance:

Some cheap "MTB" Shimano V-brakes: 103mm/31mm = 3.3x
Shimano BR-R353 "road" V-brakes: 86mm/31mm = 2.8x

The mechanical advantage of V brakes cannot be adjusted as opposed to that of
cantilever brakes. The mechanical advantage of V brakes can vary from frame to
frame and from fork to fork, as the location of pivots does not have a standard
with millimeter level accuracy.
Final mechanical advantage:
The final mechanical advantage (multiplication of lever mechanical advantage
and brake mechanical advantage) should be between 4.0x (if you like lots of
hand force) and 9.0x (if you like little hand force). Ratios above 9.0x run out
of lever travel quickly and thus require adjusting the barrel adjuster very
often, have excessively small pad clearance, so the brakes rub if the rim is
even slightly out of true or if the rim or frame/fork flexes, and the brakes
still have lots of free motion in the lever despite the small pad clearance.
Ratios below 4.0x require very strong fingers to brake.
We can determine the following combinations to be compatible:

Old Campagnolo Record sidepulls + BL-R400: 5.1x
Dual pivot sidepulls + BL-R400: 8.1x
Surly LHT + BR-R550 cantilevers + BL-R400: 7.7x
Cheap "MTB" Shimano V brakes + cheap Shimano flat bar V brake levers: 5.3x
BR-R353 "road" V-brakes + cheap Shimano flat bar V brake levers: 4.5x
Cheap "MTB" Shimano V brakes + Dia Compe 287V drop bar V brake levers: 8.6x
BR-R353 "road" V-brakes + Dia Compe 287V drop bar V brake levers: 7.3x
Cheap "MTB" Shimano V brakes + Tektro RL520 drop bar V brake levers: 7.2x
BR-R353 "road" V-brakes + Tektro RL520 drop bar V brake levers: 6.1x

Based on this, it can be concluded that Tektro RL520 is probably best paired with "MTB" V brakes and Dia Compe 287V is probably best paired with "road" V brakes. With "MTB" V brakes, one obtains more tire clearance, so that's certainly an advantage.
We can also determine the following combinations to be incompatible:

Cheap "MTB" Shimano V brakes + BL-R400: 16.8x (too high!)
BR-R353 "road" V-brakes + BL-R400: 14.3x (too high!)
Old Campagnolo Record sidepulls + Dia Compe 287V drop bar V brake levers: 2.6x (too low!)
Old Campagnolo Record sidepulls + Tektro RL520 drop bar V brake levers: 2.2x (too low!)
Old Campagnolo Record sidepulls + cheap Shimano flat bar V brake levers: 1.6x (too low!)
Surly LHT + BR-R550 cantilevers + Dia Compe 287V drop bar V brake levers: 3.9x (too low, may be near the threshold of acceptability on the drops but not on the hoods!)
Surly LHT + BR-R550 cantilevers + Tektro RL520 drop bar V brake levers: 3.3x (too low!)
Surly LHT + BR-R550 cantilevers + cheap Shimano flat bar V brake levers: 2.4x (too low!)
Dual pivot sidepulls + Dia Compe 287V drop bar V brake levers: 4.2x (even though this is larger than 4.0x, I marked this as "incompatible" because the braking on the hoods is still lower than 4.0x)
Dual pivot sidepulls + Tektro RL520 drop bar V brake levers: 3.5x
Dual pivot sidepulls + cheap Shimano flat bar V brake levers: 2.6x

So, it is important to use V brake levers for V brakes and to use traditional
levers for cantilevers / sidepulls. By making the V brake arms shorter, the
mechanical advantage of V brakes can be reduced, but with standard frame stud
locations, it is impossible to have low enough mechanical advantage (for
traditional levers to be usable) and enough
tire clearance. Of course frame makers can play tricks by moving the studs
lower, so that the vertical pivot-to-shoe distance is increased and then the
mechanical advantage of "road" V-brakes (such as BR-R353) can be made so low
that they can in a pinch be used with traditional drop bar levers. Still, it's
not ideal to use V brakes with traditional drop bar levers, as the mechanical
advantage of the entire system is very high even if the frame maker has played those tricks.


Chain wedging itself between cassette and gaurd Ok, so, basically, the rear cassette on my bike is giving me a lot of problems, and I'm not exactly a professional cyclist who would know where to begin so I thought I'd ask here;

The problem seems to sit with the chain going where chains shouldn't go. The other day when I was cycling along I chained gear for a hill or something, and there was a loud clunk and suddenly I could not move the pedals anymore. I got off my bike and had a look and the chain had gone beyond the casette and into the gap between the casette and the circular plastic gaurd that is up against the spokes.. It took litterally all of my strength to get it back out as it had wedged itself in there quite firmly.

I really don't know why that happened but I get the feeling something is wrong that needs fixing. I also have this odd behaviour with the rear casette, to go from gear 1 to 2, I have to twist the gear thing up to about halfway between 2 and 3, before i'll hear the chain move across, when left like this, I hear a scraping sound, and the way I stop that scraping sound is by twisting the gear thing back to just under 2. Perhaps something is misaligned?

I can only seem to use gear 1 through 4 on the front aswell but there are more gears it'll just never go into.

My bike gets knocked around alot and I guess it's abit abused, so could something have broken?

It is possible that you have damaged something but the most likely is that things need lube and are out of adjustment.

Check that the rear derailleur is vertical - if not go to a bike shop for help.

There are two screws (usually crosshead on the rear derailleur) that prevent the rear derailleur going beyond the ends of the cassette. The one that is for the big cog end needs adjusting so the chain cannot go beyond it into the plastic ring (I can't tell you which screw without looking on the web for the specific derailleur type).

The poor changing (front or rear) is probably due to the cable not moving well in its outer or cable stretch or poor adjustment. Try dripping some light lube into the end (eg thin Teflon, WD40) or if this is tricky undo the cable from the derailleur (note carefully which side of the screw it is on & remember this when replacing) and relube whole cable, checking for free movement when using the changer and pulling the end of the wire.

Re-attach the cable to the derailleur and use the adjustment nut on the derailleur to get the gears to index correctly (lots on the web about this: generally put the handlebar gear changer in the position for the smallest cog, pulling the wire taught manually & tighten the cable bolt. Then use the adjuster to get cable tightness exact for correct indexing).

If the cable condition is bad replace it and if possible the outers.


Installing an IGH in a Trek District SSB I own a Trek District SSB, which uses Trek's proprietary belt drive system. I'd wanted a bike with an internal gear hub, but they only offered a 3-speed version as an upgrade, so I decided to buy the SSB and upgrade it myself to something a little beefier.

The SSB has the same frame as the IGH 3, so it already has the cable guides for the hub. I'm going to take my bike to a local community shop to do the conversion, so I should have people on hand to help me with any problems I run into. What I am looking for help with is my shopping list (although warnings and gotchas are welcome).

The IGH 3 claims to use a Shimano Nexus 3-speed hub in the specs, but shows a picture of a Shimano Alfine hub. Would this work, plus this shifter? Will I be able to swap the drivetrain components over from the SSB to the new hub, or do I need to order replacements for anything?

(Referring to this question, it sounds like an Alfine hub should be compatible. I'm still uncertain about exactly which other components I'll need to order.)

Checked with Trek, and that is a 135mm spaced frame, so yes, that hub should work fine with it.  I would make sure of the interface for the belt drive "cog" on the rear wheel, make sure it will work with that hub.  Otherwise, that Alfine should be very good.  That shifter should work fine with that hub too.  Making that interface question the only issue I see other than building the wheel if that's your plan.  If you've never done it before, be aware it's a lot more involved than it appears.


What is the sliding bar on the bottom of my road shoe for? I recently ordered some Sidi Scarpe Zephyr Cycling Road Shoes.

Absolutely fit perfectly, however I've noticed there is a sliding bar element on the bottom of the shoe and I cant work out what it is for.

I'm going to fit some look delta cleats on them, for use in the velodrome.

Best explanation is it has the standard look cleat holes, 3 main holes in a triangle shape. However there is one vertical slot (about 2cm) in the middle of the 3 holes, that has a sliding mechansism within it, i cant work out what it is for.

Seems that is the Look Memory Eyelet, where you can attach some kind of tab to help get replacement cleats in the same position.

This Keo page seems to have a video on the subject, but I can't view it immediately ...


Slow leak that fixed itself? I noticed that my back tyre was losing pressure -- on the order of 70 psi down to under 30 psi in three days. (I pumped it up and left the bike alone for those three days.) I thought it had a small puncture, so I took the tube off and examined it very carefully, dipping it in water to find any leaks. I did not find any.

After remounting the tube and filling it up, it is currently (after four days) holding the pressure well.

Is this something to be worried about? Temporary valve malfunction or something else?

EDIT: Now, one and a half weeks since the last pumping-up, the tube had indeed again lost much of its pressure, though the pressure loss was quite a bit slower this time. I am betting the cause is a badly applied patch. (How can I find which one it is?) Should consider just replacing the tube.

In the end, it seems I had a badly applied patch that was leaking.

I dipped the tube in water (again) and there were small air bubbles coming from the edge of the patch, maybe one per second. I tore off the patch and installed a new one.

It leaked more when I rode the bike, likely due to the extra weight. When I wasn't riding it, the air loss was much slower which lead me to think that it had fixed itself. Also, my pressure checks were inaccurate, done with fingers only, which can't really tell the difference between 40 PSI (the minimum) and 75.


What road bike would suit my criteria? I own two bikes, both are vintage. Steel frames with 700C wheels, friction downtube shifting, drop bars, toe clips. One is more speedy with less comfort (fixed gear conversion), the other leans more towards commuting/cyclocross (touring).

I've recently been really wanting to get into more serious road cycling and/or cyclocross after re-starting riding bicycles this year. So far I've looked at many brands and models available to me where I live, and I'm still really unsure. I'm currently settling with Trek Madone 3.1, full carbon, used, but really cheap. It has a mix of SRAM and Shimano (105 I think) on there. I'd say my budget is somewhere between 700 to 1000 US dollars, that value is converted. Definitely not looking for anything professional, but for something that still at least has a carbon fork.

I already have fine commuters, this I need mainly for tougher exercise and recreational long-distance riding and maybe as an extra fast commuter, but not for racing, since in my country the road conditions are pretty bad and sportive cycling is rather unpopular (except for CX).

I'm also looking at B'Twin, Bianchi, Author, Boardman, Merida, Vitus, Raleigh, and some others.

Sportive Cycling ? Is your country France perhaps.

Anyway, for longer rides and tougher exercise, it all depends what you mean by longer rides and tougher exercise.

If by tougher exercise you mean more exertion then a vintage bike is perfect as it weighs more and you will get more exercise... or something. So save yourself the money and keep riding your current vintage bikes.

Personally I have a Bianchi Vertigo which I love.  The frame is carbon monocoque which makes it light and being carbon it means that I don't get as tired on longer rides and can recover faster to do more km's/miles the following day/s. That bike was a little more than your budget a couple of years ago, but you could easily pick up a full carbon bike for around your budget.


Are there any mini pumps that can be mounted on a wide rectangular frame? On my previous MTB (a hard tail from 2002), I had mounted a mini pump (not sure which brand) under/next to the bottle cage. The pump came with a frame mount and a velcro strip to secure it in place in the frame.

When I tried to mount this pump on my new bike (2018 Trek Fuel EX 8), I found that the frame mount of the pump does not fit the frame of the Trek - it's made for a round down tube, while the Trek's down tube (where its only bottle cage can be mounted) is more like a wide rectangle. The pump's frame mount doesn't fit that since the rounded shape does not fit on the bike's frame shape.

Having looked at other mini pumps that come with a frame mount, I've noticed (from photos) that most of the frame mounts seem to be similar to what I have - expecting a rounded down tube.

Are there any mini pumps that can be mounted on a frame like the Trek's? I've checked my son's Focus and my wife's Liv bike, and the pump does not fit on their frames either.

If not, is there any other clever way to mount the mini pump on the bike? I don't think I can use the seat post, since it is a drop post...

There are mini pump holders that attach directly to bottle cage mount points under the cage, and hold the pump to one side of the bottle. I have one that has long slots for the cage bolts that allow the holder to be mounted further away from the centerline of the frame and accommodate wide tubes.

You can also try mounting your pump holder on the seat tube or top tube.


DT Swiss Revolution spokes for touring? I’m building a set of bikes for my wife and I. Both are Surly Bridge Club frames, and we’ll initially be running WTB KOM Tough i40 rims with 2.8in Schwalbe tires.

I purchased some DT Swiss Revolution 2.0mm spokes to build the wheels. But I’m now questioning if these are too light.

I’m about 200lbs and we plan to carry some load on our bikes, mostly in frame packs. Mostly on gravel trails, 2-tracks, and similar.

I’ve never broken a spoke, even when riding the full Great Divide, across South America, or on any daily rides, using a mix of wheels with one being a 28 spoke.

Does anyone recommend against using DT Swiss Revolution 2.0mm spokes for this use? Should I move up to Alpine III or something in between?

Yes, do not use them here.

They will be impossible to get to full tension without windup on a rim even remotely as stout as that. What's likely to result is a wheelset that could have been rock solid will have constant issues with spokes going loose.

If you want to run fancy spokes, Supercomps are about as light as make sense here, and the 1.8mm tips give the advantage of much more breakage-resistant nipples for a given material choice, which is a nice thing on a disc brake touring bike getting off-road use.

Normal 2.0/1.8 would be the more standard choice. They make it easiest to deal with windup and get a stable build.


Guidance for buying large double saddle panniers I purchased a "Basil Mara XXL Double Pannier Bag"

Today, with a small load, they seemed to explode off and fly over the road. It appears that the stitching was meagre, which held the two straps to the panniers.

I could buy some belt strap material and use thick Nylon thread to repair and reinforce them, but doing this is time intensive I have found; I would prefer to attempt to return them and get new ones.

What advice can you give me on buying these saddled bags? Are some brands more sturdy than others or is it impossible to tell from brand alone? Street level shops I visited have a poor selection in London, these double panniers appear to be quite a rare breed - any good places to look? Recommendations?

edit

I used to use separate individual panniers, but they were small, whereas with larger panniers my heel will clip them. To get around this, unable to get a rack which extends back far enough, I attached the top section of an old rack onto my current rack:

So any saddled bag would be hanging 2 inches further back thanks to the extended rack space, and the angle means they are further clear of my feet. A bungee cord hooks over the straps of the pannier, then over/around the rear of the upper pannier to secure it.

Stronger strapped, large double panniers would be perfect - I find it a little too fiddly to deal with individual panniers

Unable to find anything suitable in my price range, and skeptical I would find anything tough enough outside of it, I spent a day sewing, and reinforced what I have.

I used nylon strap, 50mm x ~3m, and double folded nylon thread (so there were 4 threads per stitch) to replace the prior straps. I was able to loop the strap around a seam/strap/flashing which was just through the hole, you can see the threads looping over it. I attached the straps' ends taut to the bottom of each pannier.


Tips for cleaning old glue from a carbon tubular wheel I'm replacing the tubular tire on an all carbon wheel (no aluminum brake surface) and cleaning the old glue off takes a long time.  What are some tips, products or tools I can use to speed up this process?

I wouldn't use any solvents because you have carbon rims.

Hot air is the best solution. Use the heat from a blow drier to gently soften the adhesive to where it will ball up with rubbing from your fingers.

If you only have a heat gun, you can use it but be careful as you can literally strip the paint off your rims with it (or cause your rims to deform/delaminate) - so I'd only use the heat gun very lowest setting.

A stiff pencil eraser can also help bring up the adhesive.


Cold weather chain lube? My Rock N Roll Gold bike lube seems to get solid or gelatenous when stored on my unheated, but enclosed porch at colder temperatures.  Is a chain lubricated with this product still going to be sufficiently lubricated when riding in freezing (below 0c or 32f) temperatures?  Should I find a different cold weather alternative?

This can be a regional thing, but here in Germany, many are happy with Ballistol applied as aerosol and not changed during the seasons.

From a material science perspective, its viscosity is very low and has little temeprature dependence. It is also said that it is environmently friendly, to the extend that you can use it on pets, which I never tried as I found chains on my bike much more suitable.


What are the advantages and disadvantages of the different chainset designs? Over the decades there were many different crankset and especially spider designs: 4, 5 or 6 arm spiders, symmetric or assymetric, different BCDs, direct mount and probably many more.
When looking at all the different cranks from different eras, a myriad of questions come to my mind e.g.:

What's the advantage of 110 over 130 over 144mm bcd?

Why did Shimano changed from 130mm to 110mm bcd in the 90s(?)?

Are certain designs better suited for 1x, 2x or 3x?

Why did road cranks have had a 5 arm spider, while mountain bike cranks always had 4?

Why did Shimano adapt their road cranks to the 4 bolt design? And why didn't they do earlier?

I'm interested in the evolution of crankset design and the engineering line of thought behind the different designs.
Literature recommendations on the topic are also highly appreciated.

144mm: supported chainsets such as 52/42 with relatively narrow range freewheels
130mm: allowed a range such as 52/39, as freewheel (then cassette) range expanded
74mm: necessary to add a smaller ring, e.g., 30t on a road triple
110mm: this supports anything down to 33t, hence this was introduced for Shimano FC-R700 around 2005 as their first compact chainset, i.e. 50/34

Oddity:

92mm BCD was introduced for Dura-Ace triple 7703 https://www.sheldonbrown.com/dura-ace.html - the Dura-Ace was different, and 30t ring attached to the middle ring. This propagated to 7803, but thereafter Dura-Ace triple was deleted because compacts were standard

MTB:

94mm + 58mm BCD - were introduced in the early 1990s for MTB chainsets, to reflect a MTB triple , e.g. 44/32/22
104 + 64mm BCD - replaced the above with e.g., 42/32/24
96 + 64mm BCD introduced with M782 Deore XT 40/30/22. Improved the chainline for the 30t chainring compared with 104mm which works better with a 32, but not so well with 30t https://singletrackworld.com/forum/topic/what-is-that-pointless-shimano-96bcd-standard-for/
4-bolt chainrings were introduced with XTR M950 in 1996. For a while there were a choice of 5-bolt & 4-bolt MTBs chainset, but eventually this went to all 4-bolt
Direct mount is now a thing, and this reduces weight and makes things different again

Here the chainring fits directly onto the arm, so there is no BCD per se (although there are double direct mount chainsets, in which case a second chainring bolts onto the first)

One point not yet addressed is marketing. Bicycle companies are on an increasingly aggressive release schedule - and this is not true only of marketing. Whereas a consumer product sold in the 1950s might still be sold a decade or more later, this is bad for sales, in that if you have a high-quality, durable bicycle or other consumer product for which spare parts are readily available, there is no reason to buy a new one.
Therefore by releasing products that look radically different from the old ones, you mark the old ones out as old-fashioned. By accompanying your new releases with lots of marketing speak about weight and performance, you imply that the old is terrible and the new is great. This would have seen the 5-bolt MTB chainsets replaced by 4-bolt, because who wants old if you can have new?
Dura-Ace releases:

7400 - 1984 (7500/7600 are track versions)
7700 - 1996
7800 - 2003
7900 - 2008
9000 - 2012
R9100 - 2016

Shimano brought many technical improvements to chainrings in the 80s and 90s:

Uniglide
Superglide (later called 'SG-X

Specially matched chainrings, such that the big chainring 'helps' a smaller ring (1996, Dura Ace 7600)

By the time these features had reached all their groupsets, there was not much left to improve, except that more expensive groupsets would be better machined, lighter, etc.
So a (08/09 MY) Dura-Ace 7950 chainset looks like this:

and weighs 655g. At this point the chainrings were fairly lightweight being hollow ('hollowglide', introduced with 7800 & also found on Ultegra) aluminium
The (12/13 MY) Dura-Ace 9000 chainset with 50/34 rings looks like this:

and weighs 610g, thanks to the use of carbon fibre composite. The use of four-arms achieves many goals:

it makes older chainsets look outdated

This then-current Sora chainset looks dated because of the chainrings:

it saves weight as 4-arms rather than 5

it creates incompatibility - no sales of third party chainrings because they won't fit, and the numerous versions mean that customers will often buy a new chainset instead of chainring.

it drives new sales with new buzzwords, new styling, and chainrings that won't work with your existing equipment. And there's a great justification - it is lighter.

With the release of Dura-Ace R9100, Shimano did not really have much to offer, but nonetheless they tweaked the chainrings a bit so they would not work with the old chainset (which weighs the same) https://handsonbike.blogspot.com/2018/06/shimano-dura-ace-9000-vs-r9100-crankset.html
Now the Claris (R2000) chainset resembles the Dura-Ace

In fact it has little in common apart from the overall shape, as it has solid arms and steel chainrings weighing in at 1.08kg. But it will help make older (in fact higher quality) equipment look outdated and drive sales of new product.
In particular, note that whatever technical advantages 4-bolt designs might have they are not really made available to most purchasers, because all except pricey chainsets will use relative heavy chainrings so any small weight savings from 4-arms are lost to the use of cheap heavy materials.


Will carbon fork make a huge difference when commuting? I am considering a hybrid commuter bike, in particular I like Specialized Sirrus Elite Disc. This model however does not sport a carbon fiber fork. Only the more expensive model does, which I do not have budget for.

Another candidate would be Trek Crossrip, which does have carbon fork. Should I make getting carbon fork a priority, will it make a real difference on my ~13 km commute? I sometimes do ride over surfaces like this, that's why I'm concerned:

Not much difference in ride from carbon to Cr-Mo.  Over 13km not much of a factor. The carbon is going to be lighter, more expensive, and less durable.  Same bike on a budget I would go Cr-Mo.  You list two different styles of bikes and a purebred road bike in a comment.  Pick the style of bike first.  I don't think purebred road bike is the right bike for that picture.  I personally think drop bars are more efficient and comfortable for paved commuting. And on a budget used might be more cost effective.


Strange dynamo behavior Some days ago I noticed the light cast from my bike was not steady, despite I was travelling at constant speed. Checking the dynamo when engaged I noticed it was touching on the side of the tire, but below the strip where it is supposed to.

I fixed this, and after just one day of proper working the dinamo head now simply slips on the tire. I ruled out the possibility of too low contact pressure beacuse if I try to roll the wheel backward the dynamo rotates properly.

Should I check something else, or should I better replace the dynamo?

It sounds like you have a bottle dynamo. Many are constructed poorly and have matching short lifespans.

Typical failure modes are:

Friction wheel is made of cheap plastic, rubber, or pot metal -- and wears down, breaks, or flies off
The wiring was done by drunken lemurs and breaks off inside
No sealing against water/dust/salt and it corrodes to pieces
The hinge mechanism is poorly constructed and breaks

In your case, it does sound like maybe the spring that forces the dynamo onto onto the tire sidewall isn't apply enough pressure. I'd put some oil on the spring and hinges and work the hinge back and forth a few times. The dynamo may have also rotated (fallen) off its mounting bracket slightly, you may need to rotate it back into position and tighten its screw more tightly.

The good news is that bottle dynamos are cheap enough to be easily replaceable when they do break.


Headset standards: EC29 vs EC30 TLDR: Can I wedge an EC30 into what seems to be EC29 (29.8mm)
I'm in possession of a mid-90's frame with a:

Head Tube Inner diameter of 29.8mm (Which seems to class as EC29)
Threadless Steering Column at 1" (25.4mm)

Its my understanding that this makes it a threadless EC29/25.4, which to my surprise is NOT sold virtually anywhere. EC30/25.4 on the other hand is easy to find
Am wondering -hoping- that the difference between the two is so negligible that manufacturers discontinued EC29 with the idea that people simply buy EC30
thoughts?
-b

It's unclear how it came to be a JIS (EC29) frame with threadless. That combination is odd. There are some different ways it might have been hacked together, or maybe some small number of bikes were made that way. It doesn't matter. Get the frame reamed to ISO/Campy/EC30 (all names for the same thing) and the crown milled if needed, and then you can install an obtainable new 1" threadless headset on it.
Some manufacturers of basic OEM and repair type headsets use the same cup profile for everything. Taking advantage of that is one way you could in theory combine two headsets to make a good hack solution. But it would be way easier to just machine the frame.
Jamming an EC30 headset in should not be done under any circumstances. The frame will be at risk for cracking now or later.


Tubeless tyre punctured on the ride I have a question, what is the best method to fix my tubeless road tyre if I have a puncture while on a trip? I am searching for a fast method just to get home and fix it later.

The fastest way is to use tubeless plugs - bacon strips or worms. They are also used to plug holes in automobile and motorcycle tyres.

(source: Pro bike tool marketing pictures)
They are often sold in expensive bicycle-specific packaging, but the plugs itself can be bought much cheaper in bulk from sources directed to motorized vehicles.
The big advantage is that they are inserted from the outside, so you do not need to get the wheel off the bike. You just insert the strip (better covered by a vulcanizing glue, but follow the instructions) deep enough with a special fork and it remains stuck inside when you take the fork out. Before doing that you sometimes use another pick to prepare the hole.
The process is shown in this video:

If this is unsuccessful, try to insert another one, but you will likely have to deflate the tyre and insert an inner tube. Be careful for various old sharp objects stuck in the tyre. The sealant may have plugged their holes, but they can still puncture your inner tube.


Road jersey front length I went to get my first road jersey today. I found one I liked and the overall fit and feel seemed right, but I was surprised at how short the front is. I am aware that it is designed for being used while riding where this makes sense, however I don't want to walk around showing my stomach if I adopt an upright posture. Do I just need to try a different brand or is it supposed to be like this? I'm a pretty  average build and proportions.

Usually road jerseys will have different fits, both within a brand and across brands depending on the intended application.

If you have one with a short front it will likely be a tight fit intended for a racing position (i.e., low bar height) and typically combined with bib shorts which come up just under your belly button. Combined you will should not be showing your stomach even when standing.

That all said, if you are intending on riding in a more upright position, this type of jersey probably won’t be a good match as I find they can also pull across the chest in a more upright posture. These jerseys also tend to have a very tight fit, for aerodynamics, which can also be less than ideal for any off-bike situations.  (For racers there is no such thing as an off  the bike situation, even when sleeping).

I would personally look for road jerseys with a “casual” or “relaxed” or “classic” cuts.  They will be a bit longer in the front and the shoulders will have more room for riding upright. Mountain bike jerseys (cross-country) can also work well in this application.


Chain skipping on some gears I have an old cruising bike with 21 gears. A few months ago I was pedalling back home when my chain broke, and I was only able to get the chain replaced this week. After having it replaced I noticed it was 'skipping' and the problem seems to be more severe in certain gears. Now, the teeth are a 'bit' worn out (particularly in the middle gear at the front), and the 'skipping' didn't happen with the old chain (makes sense as the old one probably stretched a lot). Any idea what could be causing this?

As you asked for an explanation, why this skipping is happening, here it is:

For the beginning let's consider an unused chain on an unused sprocket. In this case the distance between the teeth of the sprocket is the same as the length of the chain links. Therefore, if you apply a force to the sprocket via the chain, the load is equally distributed over all teeth that are in contact with the chain. Due to the force the chain lengthens over time (not much, about 1-2% is enough to make the chain unuseable) which means that the chain links no longer fit the sprocket's teeth distance and also the load distribution isn't equal any more.

Instead, the tooth that is closest to the direction where the force comes from (the last one on the sprocket where the chain leaves towards the chain-blade and the first one one the chain-blade where the chain comes from the sprockets) gets the most load and therefore is wearing out a bit more than the other ones. As everything goes round and round and every tooth is in the position to wear out more than the others, the teeth will slightly adapt the valleys between them to fit the length of the chain.

If you replace now the chain by a new one while keeping the cassette the same (it would be the same if you replaced the cassette keeping the chain), then the chain doesn't fit any more to the cassette that has adapted to the length of the used chain links. If the length difference between old and new chain links is too much (as already said, some 1 or 2% are enough) the chain will slide up the shoulders of the teeth and skip into the next (or even the next-nearest) valley as soon as the applied force gets too high. One can make the components last somewhat longer by changing the chain early enough, but as both, chain and cassette are wearable parts they have to be replaced sooner or later.

It depends on different factors how fast this wear-out process will be:

Dirt and lubrication: Dust, rust, sand etc. act like grinding media which increase the friction between the chain and the sprocket and therefore accelerate the wear-out. A well cleaned and lubed drive train therefore lasts longer.
Load per tooth: The higher the force working on the sprocket and the lower the number of teeth over which this force is distributed, the faster the teeth are wearing out. Therefore it is usually the smallest sprockets on your cassette that at first show the skipping as they get quite a high load and have not much teeth which have to take this load.
Usage frequency of the sprocket or chain-blade: of course, a sprocket that is used more often wears out faster. This is the reason why for most people the middle sized chain-blade at their cranks will show skipping (if they ever come that far within the lifetime of their bike ;-).

This means that a road bike, where you normally don't have much dust and try to pedal rather smoothly without any rapid changes in force, can go several thousands of kilometers on one chain. With mountainbikes where you have the exact opposite (lots of dirt, often sharp load peaks when you go to rough terrain) the rule of thumb that I learned some years ago is to replace the chain every 2000km. Even then you will need a new cassette every second or third chain.


Any way to transport kids on a folding bike? I LOVE my Strida, but have noticed that the only way to transport kids with it is in a trailer, which seems to defeat the purpose of a compact bike.

I've seen a crazy expensive Brompton bar attachment that becomes an extra kid seat in front of your seat (Here's a thorough review of it: http://documentally.com/2011/08/20/a-child-seat-for-a-brompton-folding-bike-review/) but it doesn't seem to be available any more.

Any other options that combine any folding bike with a child seat?

In my opinion, this should NOT be done.

Bicycles are very versatile, and one can not only use a single all-purpose bike for many purposes, but also to have/design specialty bikes, as it is the case of a Strida. And, by the way, is the case with a lot of child-carrying specific bikes and/or equipment.

But, as it seems to me, a Strida is a SPECIALTY BIKE NOT SUITABLE TO CARRY CHILDREN! It has its purpose (portability and compactness), and this purpose is not compatible with child-carrying, unfortunately.

My suggestion would be to increase your fleet, just in case you really WANT to carry your child on a bicycle, which by the way is an EXCELENT EXPERIENCE with no age limit! (only size/weight limit)

Hope this helps, and I didn't mean to be rude or disappointing, but concerned with the child's comfort and safety.

(by the way, transporting kids ALWAYS defeats the purpose of compactness, whatever "compactness" might mean...)


Tube puncture over spoke, but rim tape fine I have a puncture in my tube on a bump in the tube that coincides with a dip in the spoke hole, and am not sure if I need to replace the rim tape or not.

I have seen numerous posts about spoke induced punctures recommending either new rim tape if broken or filing the spoke down. However, over the spoke hole where my puncture occurred, the rim tape (which appears to be cloth tape, I did not install) seems fine, although a little off center but still covers the holes. There is nothing sharp, no holes in the tape, or any visible damage to the tape.

Is the puncture simply unlucky, or is there an issue with the tape, even though I cannot see any problems? I am not sure if the dips in the rim tape, which cause bumps in the tube, is an issue. From what I've seen, this is a common occurrence.

Of note, the bicycle has not been used for a couple months over the winter.

I would recommend replacing rim tape with a modern plastic one. You could inspect the existing cloth one, but then you would need to remove it to inspect the spoke ends. Cloth tapes often don't survive removal.

When the tape is off, inspect the spoke ends and the nipples. If one is sharp, use emery paper to remove the burr. Do not use a file: a single filing always avoids removal and causes another puncture.

Repair the tube and do whatever you think will bring luck - punctures like this can be tricky to solve.

It's possible that the cause was grit that happened to work it's way in under the tube, and subsequently fell out, but the hole looks like a spoke puncture to me.


Are disc brake post mount adapters compatible for both front and rear? Post mount (PM) is a standard of brake mounts. Adapters are used to suit larger rotors. When I go to a shop, I see that apparently there are versions labelled as front or rear specific. On the other hand I see models which seem to work for both. This at least applies to shimano mount adapter.

Are disc brake post mount adapters always compatible for front and rear? Or if not, why are there differences?

I actually can answer it now myself.
Shimano has "rear" and "front" adapter. This is a relict from the time where post mount adapters were not used yet on the frame and therefore post mount were only for the front.
See this chart from Shimano
Other brands like Avid/SRAM don't even distinct between front and back.

Post mount adapters are in general compatible for front and back, making the front/rear label obsolete.

Source:http://forums.mtbr.com/brake-time/rear-shimano-adapter-160-203-pp-can-i-use-front-mount-1083866.html


Dealing with a scrape (cleaning a wound)? A couple weeks ago I bought a new road bike for commuting to work with. Part of the commute is along the beach bike path, so there's usually some sand on it. Last week my tires slipped on the sand and I scraped my leg a bit. There was quite a bit of blood and a lot of sand in the wound, but luckily I had brought a rag with me (it was clean, but I brought it thinking I might need it to wipe chain grease of my hands) and some sanitizing wipes so I was able to do a decent job of cleaning it until I got home. I used the rag to wipe up the blood so I could see what I was doing and also to wipe off as much excess sand as I could. I then poured some of my water over it, then used the wipes to clear up some more of the blood and try to get rid of more of the sand. I was about 12 miles from home and this was all I did before I got there.

There are few questions I have at this point.

Was there something else I could have done about the sand? I REALLY didn't want a ton of dirty sand in an open wound, but I also didn't want to rub the sand into it either.

Should I have used the ocean water to clear away more sand and further sanitize the wound? I considered going to the water to help cleanup, but I didn't want to get my feet sandy and socks wet, and wasn't sure if it would even help at all.

Should I have done anything else before biking back/while biking back?

It's been more than a week, and each day I've been putting hydrogen peroxide on it, letting it get as much air as possible, and then putting a band-aid on it. I'm a little concerned though, because it hasn't scabbed yet. It seems like the band-aid is absorbing everything that would be forming the scab. I would leave the band-aids off more, but I'm still biking into work and wearing jeans there. How should I be taking care of the wound now?

Any advice is appreciated!

The ocean is not sanitary! Especially around major cities, so if you were on a bike path, there is a good chance you are close enough to civilization to where the ocean is not good for your wounds. I grew up in a beach house in Hawaii and know that until the wound closes you don't want to go swimming, you can get it infected. Happened to my foot, frekn SUCKED! Samoans wash off in the ocean after they get tattoos, but they are not as industrialized as we are.

The sand itself is not really that bad, not as bad as the dirt that is mingled with it. Washing it out with clean water and covering it with that rag, as long as it didn't have grease on it, should have been good enough to get you home where you could clean it better. The problem you are having isn't so much with what you did the first hour or so but sounds more like what you did after you got home wasn't enough. Hydrogen peroxide is good, keeping it clean, make sure there is no sand in there. Band-aids are supposed to take the place of the scab, so that is why you are not scabbing up.

If you are sure it is clean and you keep it clean with fresh bandages you should be OK. Some wounds take 3 weeks to start to look better. If the skin around the wound looks red and swollen (as opposed to scraped up from the road rash) then you might need to break down and go to a DR. I hate going to the DRs more than the any one I know, but there are times when a bunch of people you don't know giving you medical advice just isn't good enough...


Can hubs last forever? In theory, could a bicycle hub last forever if you kept overhauling it (and getting new spokes and rims and etc.)?

I'd like to know about all the hubs, but what really interests me is whether or not cassette hubs and front hubs can be overhauled over and over and last 'forever'.

If the shell is aluminum and we're talking about the whole thing and not just the bearing races, the literal answer is flat out no, because aluminum doesn't have a fatigue limit. It will crack eventually.

As to the question of can a hub bearing race, real or hypothetical, last literally forever in any kind of use, that's the kind of question everyone likes speculating about but I think you need a bearing engineer to begin answering, so I'll say I don't know.

In practical terms the answer is most cups/cones with enough preventative overhauling can be made to last a very, very long time, much longer than they normally do. In my experience for a nicer hub with very hard, precisely made races it's more or less indefinitely. I've tried to keep more modest hubs going the same way and wound up wearing them out despite my best efforts, but I'm heavy and ride where it's wet.

There's a side conversation about using ball bearings whose hardness is a good match for the races, which is a topic usually glossed over in bike shops. I don't know the details but I've come to suspect it can matter quite a bit in the long-term lifespan of a hub.

How much flex the axle is experiencing is also a pretty major factor over time.

All freewheeling mechanisms wear out eventually as far as I know.


Maintenance for a single speed bike I love biking. And I also love maintaining my bikes. This is the first time I've gotten a single speed road bike, specifically this one.

My question is, for maintenance purposes, what should I look out for? I've considered getting a truing station, but I'm not too sure that's something I need to worry for a single speed road bike?

Thanks!

You will need to maintain:

tyres, chain, brakes; less frequently, chain ring, freewheel (or sprocket); even less frequently, bottom bracket

Their beauty is their simplicity.

By all means get the kit to true your wheel, but that again is something that I'd lump in the "even less frequently" category.


What would be some good and affordable mountain bikes for a beginner? What would be a good bike which would be low priced and work for a rookie?

Forget about chain store big box stuff  - cheap, nasty and comes with no support, They typically ride like pigs, and are usually exceptional heavy.  You get exactly what you pay for  - I won't put by 10 year old on one.

Cheapest is second hand, next cheapest is last years model on 50% mark down. Either way, go visit the LBS's around you and find one that has lots of kids bikes - its a sign they know about tight budgets. They also tend to be keen on the returning customers (kids grow out of bikes really quickly), so tend to give good service despite you not putting downs $1000's on a flash bike.

Do not pay sticker price. negotiate.... You will also need things like pump, helmet, spare tube etc. The LBS will also make sure you get the right sized bike.

If they are still out of your price, ask if they will check a second hand bike if you bring one in. A few dollars spent doing this and you will end up with a better bike for less money than a chain store bike.


Identifying replacement freehub I’ve been tasked to source a replacement freehub, any ideas what this type would be? Might be obvious forgive my ignorance!

Forgot to mention, it’s from a Marin bike. That’s all I know so far

Looks to be the standard Shimano RM30/RM33 variant.  The freehubs are different for 7speed vs the 8/9/10speed versions, so double check the speeds before replacement.


Removing powder paint from threads Bought a aluminum frame with rear suspension, got it sanded and powder paint. While they matched the color perfectly, it's smooth and evenly distributed BUT UNFORTUNATELY totally forgot to cover any threads.

Managed to remove the paint from bottom bracket threads, seat post tube and frame head tube with a copper brush, sandpaper and gently using an awl.

Problem is the #5, #6 threads for equipment and derailleur which is a part of a frame.

Could use a tap on #5 and #6, but the threads aren't damaged so there's no need as they are undamaged.

Any way to remove the paint chemically? Tried a hydrocarbon solvent that I left for 4 hours without slightest effect.

Taps are useful for cleaning threads, and much better than forcing a screw down the hole (though that can sometime be enough).

Derailleur mounting bolts are an unusual size, but assuming you've got a removable hanger that should be held on by a normal metric screw (M6).  Metric M5 screws are common for bottle cages, mudguards etc.

Normally you'd put a few drops of oil on the tap for actually cutting a thread.  When cleaning a thread, grease can be better as you'll pick up more of the muck with it (and leave the threads nicely greased).  If you've got a full set of taps, a second cut tap or even plug tap is enough for cleaning threads, and easier to start without cross-threading than a taper tap.


Tube compatibility for given tyre dimensions My tire says: 700x40c  40-622 , is the tube in the picture a perfect fit?

Assuming your rim is drilled out for a Presta valve, this tube should be suitable. If your rims are deep (you would know if you had them), you may need a valve extender.

If you have a rim drilled for a Schrader valve (kind on a car tire), it is not recommended (if you want to use it, you should use a valve grommet as noted in this answer) since the larger hole may allow for some damage to the tube, or better yet, buy a tube with a Schrader valve.

A Presta valve rim is 6 mm, Schrader is 8 mm.


Italian bottom bracket Shimano BB-6400 fixed cup tightening - what tool? All,

I have a Shimano 600 Italian-threaded bottom bracket (BB-6400) and after riding with it for a few weeks, the fixed cup is loosening. I've since read up about Italian BBs and learned that the correct amount of torque needs to be applied to the fixed cup, somewhere in the 600 in-lb range.

My guess is that my HCW-4 isn't quite cutting it to get me to that level. I'd like to tighten it correctly and am looking for the right tool. If I'm in the market for a torque wrench, what tool or combination of tools will fit the 36 mm cup and allow me to reach the right torque?

Thanks.

This is the tool you want, combined with any torque wrench with the proper range.

There are a number of applications where a torque is specified by the manufacturer, but no tool fitting for a torque wrench is available.

The BBI Torque Wrench Adapter allows you to attach any "normal" wrench to a torque guage, and get an accurate measurement of the torque applied to the fitting.

I've used it with pedal and cone wrenches primarily, but it would work well with the HCW-4 on a fixed cup application.

Barnett's Bicycle Institute Torque Wrench Adaptor


Is 13 years too old for an otherwise new-condition tire? I was reading some product reviews for bike tires and came across a complaint from a customer who had received "new old stock" tires. Here's the relevant part of the review:

  Feb 07, 2020

  The two tires I received had the manufacture date stamp inside the
  tires of 2007 !!! THIRTEEN YEARS OLD RUBBER !!! ...  In reading these
  pages you have seen reviews stating premature blow-outs, and greatly
  diminished tire wear. Both are symptoms of OLD rubber. ... It would be
  a good bet that this supplier bought-out some distributors ‘old stock’
  for pennies-on-the-dollar. Let HIM eat his investment, not you. ...
  See the date stamp in the attached photo, both tires had the same
  stamp...

(source)

The review correctly states that other customers had complained about severe blowouts after relatively short miles, suggesting they too may have received tires too old to be reliable.

This seems plausible; but on the other hand I have some bikes with pretty old tires without problems. Of course riding conditions may also play a role.

In summary: is there a valid concern about otherwise new-condition tires that are 13 years old being unfit for use?

Note: I'm not asking for a judgement of this specific tire. It's just an example that prompted the question.

A 13-year-old tire may be rideable for a few years, but it wouldn't be fair to sell it as new. It just won't last as long as a new one would, and the hardened rubber will perform worse and possibly wear faster.

So, not necessarily "unfit for use", but definitely "unfit for sale as a new one". But depending on storage conditions and the tire, even a few years can make a tire unusable, such as obvious hardening or visible cracks.

As for the particular review linked in the question, it seems the buyer has misread the date code.

The page identifies the tires as Schwalbe Marathon HS. The Schwalbe Warranty Page has this photo of their production code:

The format appears to match the one in the question, but it still leaves at least two reasonable interpretations:

Day/Month/Year: giving dates of 20th July 2018 (question) and 26th September 2018 (warranty page).
Week/Year: giving dates of week 20, 2007 and week 26, 2009.

But, it appears that Schwalbe has changed their production code format with an extra digit in 2010 or so. Older sources, such as this recall from 2009 show a code that has only 5 digits before a letter:

Based on this, I'd say the format is Day/Month/Year and the date on the tire is 20th July 2018. It still makes the tires somewhat old to be sold as new, but not terribly so.


Gears, distance, cadence = Speed My bike is a Giant "Revolt" and I have a speed/Cadence sensor (from Giant). It doesn't always record accurately. But my question: I'm looking for a Chart that gives me the distance traveled & speed when I'm in a specific combination of gears with a constant cadence. So I'd like to know from this chart if I have gears(front & back of course) with 'x' number of teeth and my cadence is ie 65rpm's what speed am I going and what distance have I traveled.

Sheldon Brown's gear calculator shows you speed at certain cadences (in multiples of 20 rpm) as a function of chainring size, cassette size, crank length and wheel size.

For what its worth, most people should be using a cadence in the 70-90 rpm, so you're on the lower end.


Different hub brake behavior when standing still and when moving I recently switched to a bike having hub (roller) brakes and hub dynamo, so I am pretty new at this kind of brakes.

I have noticed that if I pull the front brake lever when moving, the brake engages almost immediately, but if I pull the lever when I am standing still the lever goes almost freely until the end of its range before I feel some sort of resistance.

Is this a normal behavior for this type of brakes?

After the behavior got worse, with even a sudden and complete blockage (luckily at low speed), I took the bike at the LBS.

The brake was not properly remounted after a maintenance, removing it and placing it back solved the issue.


What went wrong with my bottom bracket spindle length calculation? Here's the facts:

My bike frame requires a 70 mm Italian threaded bottom bracket
I'm going to use a Nuvinci N360 IGH which requires a chainline of 49 (± 0.5) mm.
I have Andel fluted cranks, which according to at least couple of sellers should require a 110 mm bottom bracket with a JIS taper. And at least this seller says that 110 mm will produce a chainline of approximately 42 mm.
I have a 3/32" chainring

I decided that I would buy a Shimano UN55 bottom bracket, as it was quite widely praised as a good basic bottom bracket.

Here's the assumptions I made:

Shimano bottom brackets are symmetrical
I need +7 mm on the drive-side, so I need 14 mm longer bottom bracket spindle

I ended up buying a UN55 70x122 bottom bracket. However after crank installation I noticed that the combination gave me a chainline on 53.5 mm (chainring normally installed) or 46.5 mm (chainring installed on the "inside" of the crankarm).

So where did my calculations go wrong?

So far I've considered the following things:

What if the expected chainline was 43.5 mm instead of 42 mm? But that would have still caused a smaller error than what I am seeing now.
What if the 122 mm spindle length is something special reserved only for triple cranks? However, I've found no info that it should affect the situation this way.
What if Italian threaded Shimano bottom brackets use ISO taper instead of JIS taper? I've found no info to back that one up, and in that case, according to Sheldon Brown, the effect should be the opposite than what I am seeing now.
What if the cranks are really using ISO taper instead of JIS? That would explain the difference I'm seeing now. But on the other hand, quite many sites confirm that the cranks should be used with a JIS tapered bottom bracket.
What if on non-triple cranks the chainline is always measured "from the middle", like on double-cranks. This one I'm actually not so sure about; but I though that on this kind of single-speed cranks it would be measured from the chainring instead.

Of course I could (and actually may) go with the easy route and just order a new BB with a shorter spindle and hope it fits. However, as I try to learn bicycle mechanics, I'd really like to understand the math around this issue. As an added bonus I'd be very glad if someone could also explain the optimal UN55 spindle length that I should try to find next.

I went to take pictures of the BB installation as @Batman suggested. After removing the crank arm, I actually noticed an offset of 1-2 mm on the drive side, like @mattnz anticipated. However, I also noticed that there was a gap of about 1 mm between the frame and the BB lid:

After this observation I googled a little bit, and learned from this forum thread that the drive side main body of the BB should be installed before the non-drive side cup. I had installed the parts in the wrong order. I loosened the non-drive side cup a little bit, I was able to screw the main body in a couple of turns more. This eventually resulted as a chainline of 50 mm, which I find totally acceptable, as my target was 49 mm. The non-drive side cup sticks now out about a 1 mm or so, but the above mentioned forum thread suggested that this is OK as well.

After the corrected installation, I can assure (for future reference), that at least this my UN55 70x122 bottom bracket does not have any offset at all; length from end of the spindle to the center of the frame is equal on both sides.

I think that I've found answer to the math side of my question as well:

By combining info from pages 16 and 34 of this PDF I was able to find out that 122 mm Shimano BBs should give a relative chainline of +8 mm compared to the 110 mm ones. So if 110 mm BB should give a chainline of 42 mm with my crankset (as was the assumption), 122 mm should give 42 mm + 8 mm = 50 mm which is exactly what I'm seeing now.


Would a carbon fiber fork make a significant difference? I have a Giant Escape 2012 that i love.  I ride it more than my road bike. Ive recently switched from 32mm to 28mm tires and can notice the improved handling and speed. Is a carbon fiber fork a good upgrade? I'm mainly looking for upgrades to make my bike lighter. Also, what size would I need? I cant find my bike specs online.

No, it is not a good upgrade.

The fork change could save some weight, up to about 400 grams. This is less than difference between full and empty bottle. The ride quality may or may not change depending on your current fork and the replacement.

If you can't look up the specs of your bike, you can always measure yourself, the critical measurements are steerer tube diameter, steerer tube length (new forks come with extra and you are supposed to cut them, just don't get too short one) and distance from fork crown to axle.


Loose bolt on stem, replace? My stem is secured to the steerer with two bolts. One bolt is strong. The other is loose. Replacing the bolt wont fix it, because the material around the bolt is not that strong anymore (small pieces coming out). Pls see attached screenshot.

How can I fix that? Is it secure?

Having just one bolt to bear the load isn't enough. The main good option would be to replace the stem. It's chunky so helicoiling would likely also be fine if you found a shop to do it cheaply enough.


Help me fix a loose pedal-arm on a fixie! Basically, after a few months of riding my bike, the pedal arms start to loosen up every few weeks after skidding/backpedaling. I ended up having to pedal with one foot for at least 2kms today (I know, bad idea).

What is a possible fix for this problem?
I definitely saw metal dust from abrasion. Also may have seen a bit of worn thread on the pedal-arm. Someone told me to replace the self-extracting bolt on the NDS. There’s more to see in the photos I’ve added.

I greatly appreciate all your contributions, this really helps me out.

What is a possible fix for this problem?

Loctite.  Blue.
I have an FSA-based SRM power meter where the self-extracting crank bolt simply will not stay properly torqued without using Loctite.  That's probably pretty similar to the problems you're having. And I'm not backpedaling or skidding with that bike...
I bought the SRM crankset used, so maybe it was ridden with a loose bolt and the crankarm/spindle interface was damaged/distorted prior to my purchasing it, similar to what happens with a square-taper crankset.
I replaced the self-extracting bolt, and that didn't help.
But using blue Loctite works for me.
If that doesn't work for you, you might have to replace your crankset.
I don't recommend red Loctite...


Whats the difference between a cyclocross and cyclocross-commuter Could someone please tell me the key differences between the what people would call a cyclocross bike and a cyclocross-commuter?

I have seen people saying bike x is not a true cyclocross bike etc.

A cyclocross bike is designed for cyclocross racing. This typically involves riding as quickly as possible around a muddy field.
So for a cyclocross bike:

Lightweight frame and forks, usually aluminium or carbon
More 'aggressive' riding position, with lower down bars
Nearly horizontal top tube, to allow carrying it over your shoulder
Knobbly tyres, and plenty of mud clearance

Whereas a commuter bike is designed more for comfort, and carrying luggage as required. So it may have:

Heavier frame and forks, may be made of steel.
Mounts for fitting a pannier rack, and full mudguards.
More 'relaxed' riding position, often more upright.
Mostly slick tyres, often heavier, with extra puncture resistance.
Components may be heavier, but more durable, so they last longer without much maintenance.


Shimano Revoshift repair My bike has a grip shift (Shimano revoshift) which isn't shifting through all 8 gears.  Even with the gear cable removed (it recently broke) it will only shift through half of the gear numbers and some blanks.  It is almost as if the number dial has slipped around the shifter.

It still sort of works ok but I can't use all of the gears.

Is it just a broken shifter that needs replacing or is it something that can be fixed?

Thanks in advance for any advice.

KR,
Pappaun

It depends on how much you value your time. Taking one of these to pieces and putting it back together again is do-able but may not give you the fix needed, whereas, buy the new part and it might save you time.

To give it a go, type in 'revoshift' into http://techdocs.shimano.com/techdocs/index.jsp and pull up your manual.

And personally, if I were you, I would give it a go.


Should I remove foreign objects from my tyres if I'm running tubeless? I have been running a tubeless setup on my bicycle and have picked up a number of foreign objects (e.g. thorns and glass shards) in the tyres. The sealant is doing its job and I am not losing significant amounts of air from any of the punctures. Given that the tyre is holding air is there any value in removing the objects?

In general, I would recommend removing thorns and other debris even if the sealant is holding. Tubeless sealant is typically latex based and designed to adhere to rubber, not glass or wood fibers. As mentioned in The Benefits of Going Tubeless the sealant could fail to seal around a foreign object and leak air until it is removed. While not immediately obvious a poor seal could allow a slow leak which will require reinflating the tyre more frequently. The usual argument against removing thorns is that you will be reopening the puncture and losing air as the sealant plugs the hole again, however given you are free to do this at your leisure you should be able to reinflate the tyre at the same time.

The major reason to remove foreign objects instead of letting them build up is in case you get a puncture so severe you need to use a tube. As DWGKNZ mentions in their answer to How do you fix a puncture on tubeless tires? if you leave thorns in the tyre you will need to remove them anyway when putting a tube in and it'd certainly be more comfortable to remove the majority at home instead of on the side of a trail.


Oil leaking from right gear shifter? The right gear shifter on my bicycle (which controls the gears on the rear wheel) has some wear holes and appears to be leaking oil over the shifter (see pictures). I'm fairly new to cycling, though, so I have no idea. My dad and I share this bicycle, and I don't think he rode the cycle with oil all over his right palm. I tried cleaning off the oil with soap, but it seems like it's still there.

Is there oil present inside the right gear shifter when the manufacturer built the bike?
Are the holes in the right gear shifter a possible cause for oil appearing on the shifter?
If so, what should I do about it? How should I go about fixing it?
If not, do I still need to worry about the wear holes in the shifter?

My dad bought the (Roadmaster) bike at Walmart about a year ago. It gets used pretty regularly except when it's snowing outside or in really bad rain.

There shouldn't be any amount of liquid oil in the shifter, just some grease.

Looks like some grease is getting out of the holes in the rubber grip and onto the outside.

Regular detergent is not strong enough to wash away grease. You need a proper degreaser product. The citrus based ones are quite good, and available at regular hardware stores.

Obviously the rubber grip needs to be replaced. It's letting grease out and - maybe more importantly - water in. With a Walmart level bike, replacing the whole shifter isn't very expensive. Figuring out what exact model the shifter is can be  difficult though.

The rubber grip should not be worn after a year's light use. Perhaps it was damaged by something sharp. You may be able to glue the holes shut with a rubber cement.


Force needed for tire and rim (removing/inserting) Until now I used 26" rim with Schwalbe Fat Frank and Big Apple (range 2.15"-2.35"). Except for initial prying when removing tire I can perform all operations with my bare hands without a sweat.

Today to my surprise I literally fought to remove WTB Resolute 42C from the rim (28") and risked breaking the tire lever when inserting back Specialized Sawtooth 42C tire.

Why such difference? Is it old vs. new? Wide vs. narrow? Or is it just this particular tire against other one and there is simply no rule.

There is a small acceptable range of bead diameters for a given rim size, hence some tires are a little bit loose, some are tight.


will any shimano pedal fit any shimano crank? I bought a second hand boardman cb pro mountain bike. It came with no pedals (as expected) but the guy gave me some 1/2 inch screw pedals, flat basic ones.

But they don't fit. The screw diameter is way too small for the thread on (I believe you call it a crank).

The crank is shimano Fc-m542.

The bike is relatively modern. (within 5 years, at a guess).

Is there a specific size pedal I need to look for so it fits tge thread / hole?

Normally, one piece cranksets use 1/2" x 20 tpi pedals. Three piece cranksets use 9/16" x 20 tpi pedals. Old french cranksets use something else.

You find one piece cranksets on old American bicycles or some very low quality bicycles (such as those you'd get from Walmart). Almost all other bicycles use three piece cranksets.

So, you need a 9/16" pedal. Remember to grease the threads before installing the pedal and the left side pedal is counter-threaded (tightens counter clockwise) while the right side pedal is threaded normally (tightens clockwise).


Straightening bladed spokes I have a wheel set with bladed spokes and they regularly become twisted such that the spokes are no longer lined up with their thin side to the wind, as indented.  They twist so that the broad side of the spoke is breaking the wind instead.

This has to be a pretty common problem and I was wondering if there is a good way to straighten the blades so that they are aligned properly?  I usually go at it in a pretty crude manner, taking a leatherman or some other multitool and carefully grabbing and turning them straight.  The problem is that the tool is usually too big to fit properly in between the spokes and there isn't enough room to twist the spoke back completely straight.  It's especially difficult when there is a lot of tension on the spoke.

Are there any methods or makeshift tools that one can use to straighten bladed spokes without the risk of damaging them?

I had the same issue and ended up taking a piece of very hardened plastic and melting a thin channel out of it the same width as the thin side of the spokes.  In this manner, I could hold the blade in place while I was truing the wheel.  I never had problems with them twisting when I wasn't cranking on the nipples, however.

To be clear, I heated and melted the channel in the plastic with an unused spoke (extra from building the wheel) and then threw that spoke away.  I would never recommend heating a spoke currently in, or intended to eventually be used in a wheel.


Clanking sound from the bottom bracket when I pedal My MTB, having not received much TLC lately, was making a lot of squeaks and noises.
After a long-overdue clean-up and lubrication of the drivetrain, most have gone away.
However there's something still making clicking (?) noises, and it seems to come from the bottom bracket area.
It only happens when I pedal, regardless if I use a lot of force or not, but not for super-light action - like pedalling by hand, with the bike on a stand.
See (and hear) this video.
Any suggestions to what may be causing this?

My first suspicion is the chain hitting the front derailleur cage. The clicking is fairly loud and occurs continuously whenever you pedal. If the bottom bracket bearings were damaged you would feel it through the cranks rather than hearing it and there would be clicks once per crank rotation.
It's also possible that you have chainsuck going on. A worn chainring can hold on to chain links past the point where they should disengage, then they pop off the chainring teeth with a click.
Put the bike in a workstand (or have a friend hold the back wheel of the ground), pedal manually and inspect the crank area to see where the noise is coming from. Try different gear combination to see if that makes a difference.
You can also check the bottom bracket bearings - turn the crank by hand and feel for clicks or 'notchiness'. Push and pull the cranks to check for any play in the bearings.


Can I grease a crank spindle/bracket without disassembling the crank set? A bit of history: the grooves on the spindle are partially destroyed/skewed by cycling with a loose crank, so I applied a lot of force to a hexdriver to get the crank arm on. Now, it would be quite hard, if possible, to disassemble it. I got the bicycle on a garage sale for a price of two cups of coffee.

The crankset began to creak.

Can I get a grease on it without disassembling the crank set?

I tried leaving the bike laying on a side and pouring WD-40 on the side of crankset. It helped for some time, because it's fluid enough, but WD-40 is not a proper grease; it needs to be reapplied once in few days, and then it makes it worse because it also acted as a solvent for the original grease.

Maybe there's a grease I can heat up to about 80°C to make it fluid enough to get into the crankset and curdle inside?

I don't have access to special the tools like crank arm remover, or whatever else could be needed. I only have generic wrenches, screwdrivers and hexdrivers.

I would highly appreciate NOT receiving these answers/comments:

invest time and money -- buy proper tools and disassemble it. I recognize this is probably the right answer; but it's just a creak of a bicycle that costs me two cups of coffee.
replace the whole crankset. I'm pretty sure I can get a few more hundred miles out of it and replace it later. Plus, it costs as much as a new (used) bicycle - more than this whole one, - plus the time and tools to install.
take it to a bicycle shop. I live in a very expensive area; it will probably cost me more than buying a new bicycle.
WD-40 is not a (proper) grease, use the right one.

Thank you.

I'm going to offer the contrary answer - why not fix it properly?

Summary:  Your spindle/crank interface is damaged, so the crank has been forced onto the spindle and is now at a high state of torque.  Its confirmed that the spindle is damaged and likely that the crank arm is now damaged as a result.  And the rest of the bike is OK.

So the worst case is that your BB needs replacing, and that the crank arm is damaged enough to need replacing too.

Replacing the BB with a nice new cartridge will give you a new spindle/axle, and it will give you a much better pedal feel.   You will have to match the new spindle to your crank's interface, being square taper or octalink or whatever.

You won't know if the crank's a writeoff till you get it off.  So pick a time when you don't need the bike for a bit and can work on it.

Consider that had you changed the BB for a new cartridge, the crank arm would have gone on easier and not been damaged.  By cramming it back together, you've made your problem worse.  Do it right sooner, not postpone till later.

Just cos the bike had an initial cost to you of 2x coffees, doesn't mean its junk.  You could look for another donor bike to salvage some cranks, or check Ebay/craigslist/gumtree/etc.

Note that your left and right crank don't need to match, they just need the same fittings and same overall length.

As for getting the current one off - leverage will help.  If the bolt shears then the stub will be in the BB spindle/axle which is trash anyway, and the new one will come with replacement bolts.

You don't need a LBS for this - its dirty but its not hard.  The only tool that will be odd is the fitting for the ends of the cartridge.


Is it worth buying a second hand classic road bike for commuting? I am looking for a substitute for my commuting bike. It is a cheap second hand general store bike. It do the job but just don't worth keep maintaining. But at same time I have to keep my bike outside for 10 hours a day in place where several bikes where already stolen (attached with cheap bike locks but still a fact). So I am afraid of leaving a decent bike there.

I checked second hand bikes pages and looks like there is a lot classic second hand old road bikes for sale really cheap and from big brands.

But I am not sure how much work a bike from 90s need and what I should check if I am buying one or even if it is a good idea.

A (decent) bike from the '90s would not be significantly different† from (a decent) one only a few years old except for a small weight difference and possibly lacking brifters, which are de facto standard on road bikes these days. This statement is of course excepting top-of-the-line superbikes made of carbon fiber and dragon's blood.

Check it for stuff like rust in hard-to-see places (small bolts etc.): This is a good sign of how well (or rather poorly) the bike was taken care of. If there is no or minimal rust, it's probably been taken care of well enough.
Look over the frame for any signs of crashes: Big dents, cracks, fissures, etc.
Check if the headset wobbles or not: It shouldn't, and if it does, it might need to be replaced, which would be very expensive.
Check how worn the chain is: If it looks horrible and probably has never been changed, that's a warning sign.
Check the teeth on the front chainring(s): If they are starting to look like shark fins, the chainring will need to be replaced.
And of course, just ride the thing and see how it feels.

† "Significantly different" means from a mechanical/engineering perspective: IMHO, some of the ugliest bikes I've ever seen were from the '90s.


Biopace chain rings and front deraileur rub Turns out my front chain rings are biopace, after I thought they had disappeared!

I've got a problem with the chain rubbing the front deraileur at a certain point every rotation. I only get this in the highest gear on the inner ring and it happens from about the 4th gear when on the outer ring. getting gradually worse when changing up to the highest gear.

Not sure if it's a trim or height problem or both :S

when in the small inner ring height should not be a problem.

But it could be height issue when on the highest gears on the outer ring.

Setup

Dura ace deraileur front and back
105 cranks and chain ring
unknown back sprocket set

Keep in mind that there are 5 adjustments on a front derailer:

Low limit
High limit
Cable adjustment -- selects where the derailer stops for intermediate cogs
Height above crank
Angle on seat tube

For subtle chain rub problems sometimes adjusting the angle (very slightly!) is the best approach.

But remember that if the rub is only once a revolution it suggests that the ring, arm, or crank is bent.


Okay to use new KMC master link on old KMC 11spd chain? I took my 11spd KMC bike chain off a few days ago to give it a good cleaning and re-mounted it to the drivetrain using a master link and park tool master link pliers. I must have not set it correctly because as soon as I went for my ride and turned the pedal the chain broke at the master link and I lost one of the pins attached to the master link.

I removed both pieces of the master link inspected the chain for bent or broken links. It looks good, I had a spare 11spd KMC master link that I fitted in the same spot and road around with no issue.

Is this something that is okay to do or now that I've had to replace the master link has the integrity of the chain been compromised?

Thanks!

Many master links from several vendors are specifically designated to be single use meaning you replace it with a new one after you unlock the old one. Which means you'll generally be fine by using a new master link.

For a moderately worn chain, adding a new link to the group of old ones means that less than 1% of your links will be a bit different (a typical geared bike has 110-116 links in a chain). It is unlikely that you will notice it.

If your chain is extremely old and stretched far beyond normal, adding a single shorter link to the mix may become noticeable, at least as a periodic sound appearing when this new link interacts with the rest of the worn drivetrain parts. In the worst case, it won't last because of that mismatch with the rest of the drivetrain.


I can remove crank arms without a crank puller, is this a problem? I'm worried the crankarms might be loose Currently, I'm little bit worried about the compatibility of my crankset and the bottom bracket. The crankset is Truvativ Isoflow, the BB is BB-UN55 (Square taper). Yesterday, after the bike hit +1400 km mark, I scheduled maintenance for the crankset. I disassemble the crank arms and the BB, cleaned them, apply grease (I use Phill Wood), and reassemble.

However, when I removed the crank arms, I didn't need a crank puller at all. This made me worried that the crank arms might be loose. So what I might want is tigthen the crank bolts. However, on the drive side, the right crank arm already hit "the limit" (see an image below) so it wouldn't go any further in.

To the best of my knowledge and according to this specification document, the BB should be compatible with the crankset. Its spindle width is 113mm to achieve 48.5mm chainline (The bike is a single speed), see a table on the bottomleft of the pdf document.

Another solution I found on the web is not applying grease on the spindle and the crankarm holes to increase friction. This is what I did. So think the crankarms are tighter right now. So far I have no problem, no creaking noise, and I doubt the crank arms will be fall off anytime soon. However, I'm not sure whether I'll have problems in the future.

edit 1:

I put some more information:

according to the pdf document, the crankset is compatible with
truvativ LE square taper BB which has JIS interface. The UN55 also have  JIS. So the crankarms and the BB should be compatible, right?
When I built the bike in April, I was noob so I put too much grease
on the spindle. I think this was the reason why the crankarms fell
off easily. That's why I didn't grease the spindle yesterday.

If you are able to seat the crank arm onto the axle such that it hits the green area you marked (i.e., it will slide all the way down the taper), then the crank arm is "worn out." The taper on the crank has been enlarged by wear or over tightening to the point where it can no longer form a solid connection to the axle. The "right" fix would be a new crank arm, but it seems like you could try the ideas suggested in the comments above. Do check the condition described by @mikes, if the axle is sticking out beyond the crank arm then grinding will not work, but then you are also likely to have quite a bit of room for a shim :-).

If you're game to experiment, my biggest concern would be that there might be cracks starting to develop in the corners of the crank arm socket from the stresses of the arm trying to rotate on the axle. Eventually those could lead to the crank arm failing at the socket.


Is this a stunt or a useful descent technique? In many mtb movies about the style "Downhill" the riders casually twist their fork and front tire at jumps, such as here and here.

Is this a stunt for "cool points" or does it aid in stability/speed in some way (as in, helps you finish first)?

Typically cool points, but it can be used to align the bike with the landing surface if the launch, trajectory and landing aren't in a straight line.


What type of Bianchi do I own? I bought this 2 years ago from a man with a lot of bicycles. It has straight handlebars and the number HOL3 1703 at the bottom of the bike. Thanks for the help.

As it says on the top tube, it's a Bianchi Main Street.

Looks like an older hybrid (probably early 90s).

Would do fine for riding around town possibly after a bit of a tune up.


Can I change my tyre size from a 20x2.20 to a 20x2.30 with out changing my rims I have a bmx with 20 x 2.20 tyres on it. Can I change them to a 20 x 2.30 and would I have to change my inner tubes as well.

As long as you have wider rims it should be okay, but it really depends on the inner rim width. An inner width of 19 - 20mm will support a 2.30 tire just fine. If your rim has an inner width of 16 or 17 i wouldn't go any bigger, not that it would be catastrophic, but you increase your chances of a blowout on a big bump or curb.

To find this measurement either look up the rims on google or measure it yourself, you're looking for the distance between the two bead hooks.

With that small of a jump though i imagine you will be just fine. Tube-wise you should be okay as well as they are made to handle a range of sizes rather than one specific size. One thing to consider is the more you pump a tube up the thinner it gets and the easier it will pinch flat and puncture. So without knowing what size tube you are running right now it's kind of hard to say. But many tubes are sold as a 20 x 2.00-2.40 so assuming these are what your running there should be no problem. If you have a 20 x 1.50-1.95 in there and it is already stretched past is usable range it may go boom.

So with the assumption you have ample frame clearance (Check your brakes too) and that your are running the correct equipment to begin with you should have no problems.


Removing square taper bottom bracket cartridge after stripping notches I have hit an extremely non-cooperating drive side square tapered bottom bracket cup.

I used a 8x1mm threaded rod to secure the tool in the cup before using the double-wrench tip to have a two feet long leverage. Someone else held the bike so that I could go full force, but the notches gave up. The tool was so tightly inserted that the bottom face of the cup got scratched as well. Penetrating oil had been abundantly put in there before and gravity had two hours to make it do it's job.

The force was applied clockwise.

So, here I am, looking for ways to drill, grind, file, cut or destroy this thing.

I think the first thing to do would be to have a way to remove the spindle and bearings. Then, the cup could be cut or filed.

Thank you for any help!

I had something like this on an old folding bike.  The owner said that he had it installed by a gorilla using loctite threadlocker.

So the fix was to use leverage, but to control it so the tool did not slip.  We had the non-drive side off and removed the axle, and reinstalled the shell temporarily.  There was some threadded rod through the BB, and we used a stack of big washers to spread the load.  This held the BB tool (a park HCW-4).   Then we used a pikey hammer to gently turn the cup.

Sounds like you have the cranks off but neither side cup.  So your best option is to rig up something using the BB itself as the shaft that holds the tool in place.  Some washers, or a short buttpipe/bushing might be all it takes.

As promised, here's the tool I made for taking off a cup that is stuck.

Here's the normal bottom cup tool with two flats on it.

Completed tool ready to turn:

Photo of it without the middle tube in place:

Making the two washers - started with large 2" washers from the junk drawer.  One needed an 8mm hole in the middle for the crank bolt, and the other need a 26mm hole to clear the BB axle.  Somewhat rough way to do it, but it works.

The purpose of this is to hold the correct too in place while you apply leverage.  Also means your fingers are nowhere near the pinchy bits.  When working alone you can now use hand leverage, and then a progressively increasing series of hammer taps to work the cup loose.

NOTE the drive side cup is left-hand threadded.  So turn it the opposite way

If you're talking about the cup on the non-drive side, then its often a different fitting, with a lock ring.  You can either do exactly as illustrated, but use a park HCW-11.    Or you can use a pair of stiltsons or some sliding lock-jaw pliers on the locking ring part.


What can I do to stop my front dérailleur rubbing against the crank arm? I recently changed the crankset of my Cannondale Synapse 5 from the stock FSA Gosssamer crankset to a Rotor 3D24 crankset with power2max power meter. This was a bit of an iffy modification to make - the Cannondale frame has a BB30A bottom bracket with a 73mm shell width for 30mm spindles. However, the Rotor cranks are 24mm. I took the bike to my LBS and we eventually got everything to mount using some Wheels Manufacturing shims (BB30-UNIV).

However, there is a problem now - the front derailleur now rubs against the crank arm as the crank passes over the derailleur, causing a very annoying clicking noise. I can stop the rubbing by tightening the high limit screw in all the way, but now the derailleur itself rubs against the chain, and doesn't have that 1-2mm clearance that is recommended.

I have a bunch of spacers that came with the Wheels Manufacturing shims, and I've taken the crank off and installed some on the drive side. This has the effect of pushing both the crank arm and the chainrings out - so the clearance between the chainring and the crank arm is still constant and small.

Is using these spacers the right thing to be doing? I'm wondering if this is a chain line issue?

I am also considering getting http://kogelbearings.mysimplestore.com/products/cannondale-bb30a-24-for-rotor-cranks but I don't really see how that will solve my problem - it seems to be the distance between the crank arm and the chainring itself...

If you already adjusted the front derailleur, there is not much to do. As you wrote yourself, the distance between crank arm and chainring is too small for your derailleur. Ask Rotor about compatible derailleurs.

The main reason to have derailleur not touch is not noise. The derailleur scratches the crank, which creates a starting point for cracks.


Do I need to take my weight off the bike to lock out the suspension? I've recently bought myself a new mountain bike (my first since my schooldays...) and it has front suspension with a lock-out function.  Suspension is new to me and I'm not sure how to use the lock-out.  It seems I have to stop and take my weight off the bike to lock-out the suspension - is this correct?  Or should I be able to operate the lock-out whilst sat on the bike and I'm just not turning the lock-out hard enough?  As I'm not really sure, I've avoided turning it too hard in case I do some damage.

Less expensive forks have a mechanical lockout. This type of lockout is only usable when the fork is unweighted. Think of it like trying to deadbolt your door when it's still ajar. Higher end forks- coil or air- use a hydraulic lockout. There's a lot going on inside them but to simplify things a bit, there are two valves in the damper of most mid-high end forks that allow oil to pass through and both only work in one direction. One allows oil to pass through when you hit a bump, the other allows oil to pass through on the rebound from that bump. When you engage the lockout on one of these forks it basically closes the valve that allows oil to pass through when you hit a bump, however the rebound valve stays open allowing the fork to return to it's original position.
So back to your original question-
No, there is nothing wrong with your fork. The lockout is working as expected and don't force it or you might break it!


Will short arm crank conversion work for me? I own an 18 speed "Columbia Journey Comfort Bike". Since having 2 knee replacements I find that I do not have enough knee bend to pedal. I have raised the seat & still cannot even do one revolution without severe pain. My bike shop says "short-arm crank conversion". He is suggesting 152 cm but I wonder if something much shorter like a 135cm would enable me to pedal? Can anybody relate to my dilemma? What size crank do I need? I am a woman 5'6" & my bike is a Men's. I just want to ride again!
Thank you.

We cannot tell you what size cranks you need.

Perhaps someone has direct or similar experience to help you with. If not, here's my advice ...

In order of preference

Talk to the rehabilitation people who (I am guessing) helped with the knee replacements. Find out if they can advise you on this, or if there is a sports physiotherapist (or similar) that they recommend. Having those people talking to each other usually fast tracks the process. At the very least I think you need to know the likely consequences of your choices. Is OK to work through some pain or discomfort? How would you know that something is wrong? The more info you have the better.
Find a sports physiotherapist for yourself. If you already know one and they can't help, get a recommendation to someone who can.
As a last resort, get a friend to support the bike while you test what movement you have. Make marks on the wall or use some other means of measuring what you can do without pain. Check if both knees have the same movement. If they are the same then half the distance that you measured is the crank length you can use. Make sure you understand the idea here before going further. Then go back to the shop and see what cranks they have that you could use.
The idea is to have an independent idea of what you need before you talk to the LBS guy again. No matter how honestly helpful he is, be prepared to get a second opinion as well.

Good luck!

Update

Web searches show that cranks can be found in many non-standard sizes, such as 130mm. Some people will take longer cranks and cut them down to the size you need. I'm sure you'll be able to get what you need! The first step is to work out just what that is.

Where your LBS could be of great help is working out what gearing you'll need with your short cranks. As you get stronger your needs may change, so keep up a good relationship with them.


Is it normal to have pins in the cup of "cup and cone"? I got a shimano hub for my front wheel and rebuilt it last November, but didn't ride much until March. Now I hear a metal on metal grating noice when riding and my best guess is that it is comming from the new hub. Doesn't happen when I just spin the wheel, only when riding and not all the time.

Took the hub apart to see what is wrong and also add more grease. When looking for damages I noticed that on one side, in the cup part, there are two metal pins. They are the two little dots at 8 o'clock on the cup. (Apologies for the image quality.) They look like how nails without heads look, except that they jut out a bit and rounded on the top.

Is this normal? Do they serve any purpose? Could they be something that was in recycled metal, assuming these are machined and not casted?

Above all, could these be causing the noise? My guess is that when the cone is pressing, the bearings can get jammed in these withoug rolling smoothly. Each pin is about 1.5mm wide and jut out about 0.5mm.

Update:
Added few clear pictures.

Last time around I used white lithium grease. I took the hub apart today and on the side with the problem grease has changed to dark gray while the other side is still white.
I will see if these flattern out over time and then replace the bearings. Or replace the hub altogether.

Thank you for the clearer photos.  From them we can clearly see that the pinheads are not in the way of the bearings as they roll around the bearing surface.

To test that, grab a single bearing and put it in the race so the visible wear band is straight down.  (ie hold the hub at an angle)
Then use your finger to roll the bearing back and forth around where the pinheads are, but stay on the visible wear track.  If you feel the lumps as the bearing rolls over, then I'm wrong and they ARE interfering.  If not, they aren't interfering.

Note I'd choose to run bare ball bearings in this hub, not a pre-assembled bearing cage.

If the marks really bug you, consider using a Dremel or some super small tool to buzz off the lump.  You might be able to scratch them off with a flat screwdriver.  Would be very hard to get a file onto that surface.   Clean the bearing surface well to remove all metal dust once you're finished.