ModeratedUser150120149

I recently bought a new (to me) road bike. This bike has a Bontrager Race Lite Triple crank. I really like the bike but not the crank. It has one annoying problem that I have not encountered with my other road bike, that also has a triple crank (Shimano 105). To shift from the middle ring to the large ring I must pause pedaling.

I don't have to pause pedaling on my other road bike, nor on any of the bikes I have rented. It is pretty common to have to reduce pedal pressure; but not pause entirely. Why this one?

After I bought the bike I had a LBS go through it and set it up. They have rechecked the bike and claim that is normal and that I just don't know how to ride it.

What can I do about the problem other than live with it?

BluesDawg

Seems strange. What happens when you try to shift as you normally would, without pausing?

leob1

First find another bike shop. Saying "you don't know how to ride it" can be a cover for "we don't know how to fix it", aside from being just a plain rude and nasty to say. It the big ring an after market part? Does it have pins and ramps? How old is it compared to what ever else you have?
I have never had a bike that you had tp pause pedaling to shift. Isn't pedaling what makes it shift?

Recycle

The chain won't move to the next chain ring if the crank isn't moving. Is it possible that you just need to ease up on the pedal pressure as you shift rather than pause?

stapfam

Only bike I have to take pressure off the pedals when shifting is the Tandem. I know the problem on this and that is an old front derailler- which is probably 8 speed- being used with a 9 speed chain. It just catches on the teeth and locks if changed under pressure but fine if we just ease off a bit.

Sounds to me as though the F.D. is out of adjustment or alignment. But I would go to a 2nd shop to get it checked out.

AdrianL

I'm currently having a very similar problem. I have a compact crank - FSA Gossamer with a Shimano Tiagra FD. For a number of months, I always rode in the big chain ring. Lately I have started using the small ring on some steeper hills. It shifts perfectly going from the large ring down to the small one but when I try going back up, I have to stop pedaling, hold the shift lever in and start pedaling again slowly. and sometime the chain will go on up to the large ring. It is frustrating.

I have had the bike in the shop several times for them to adjust things to no avail.

Today I was in the shop and they told me to bring it back in. They want to change out the chain ring. They suspect the ramps on the ring are not right for some reason.

I don't know if that is the same problem you are having but it could be.

rm -rf

A ramp problem seems very unlikely to me. Do you have a picture of the left (bike) side of the big chainring? I have an FSA Gossamer, too, and can compare it.

Is there a different LBS you can try?

ModeratedUser150120149

It stays on the middle ring.

At that point I've got the shifter cranked over to the stop. Even if I hold it there the chain doesn't go up to the large ring. It isn't frozen since I can release the large handle on the shifter and use the little one to shift down to the smallest ring.

ModeratedUser150120149

Nope, I've tried a variety of shifter movements and pedal rates. The only thing that works is to bring the shifter full over, hold it and then pause. Then start pedaling agan. As soon as I start pedaling after the pause the chain moves up to the large ring.

Interestingly I rode my other road bike last evening. This one is Shimano 105/Shimano 105 vs. Shimano 105/Bontrager Race Lite. Other than the different crank both bikes are the same. It shifts like a dream no matter pedal speed or pressure as long as the crank is rotating it shifts.

Since the crank shifter combination came original equipment from the factory I doubt there is a compatibility problem.

cyclinfool

Find a better bike shop.
I can shift my triples and my compact front DRs while pedaling and under significant pressure as well.

ModeratedUser150120149

New Info

I talked to another bike shop. I was told there is a poorly advertised problem with the Bontrager cranks, especially the Race Lite. They often have shifting problems. The only solutions are: A) Live with the problem. B) Change Cranks to another brand that is compatible with the S105 shifter, probably 105 or Ultegra.

This shop is 3000 miles from the bike and has no hope of making any money off this. Plus, I've seen the mechanic there solve a wide variety of shifter problems. So, I have a tendency to believe him.

What say y'all?

John E

Put the bike on a shop stand and have someone apply a little drag on the rear wheel while you pedal and shift. Observe the chain and the front derailleur carefully, to see if you can determine precisely what is happening. Is the chain perhaps catching between a chainring and the cage? I replaced my mountain bike's original 38T middle ring with a 40, to get better ratiometric progression, and I have to use a little care on the 28-40 shift.

Even if your derailleurs permit loaded shifting, it is always best to turn the cranks gently while changing gears.

ModeratedUser150120149

I'm not sure what you mean here. Of course I don't try to ram the gears the way one would with a race car. I try to shift smoothly and within the gear's speed range. That seems to work on all other bikes except this one. Do mean to actually pause in the shift to unload the gears?

BluesDawg

+1
I think that in this era of indexed shifting and ramped chainrings with profiled teeth, the fine art of shifting gears has been lost to most. Technology has replaced human skill. I try to shift as smoothly as possible even on my bikes that allow successful hamfisted shifting (primarily my newest mountain bike). But I get the most enjoyment out of shifting my non-indexed bikes which prefer, if not demand, a more artful touch, coordinating the various actions and components involved in a smooth shift. - flame suit on -

stapfam

I can believe it. I have heard of it happening before and it is not down to the 105 bit.

AdrianL

Latitude65 - I just brought my bike into the shop to have the large chain ring changed out. They will put an Ultegra ring on the crank - under warranty.

I'll let you know how it works out. If that fixes the problem, it's much less expensive than changing out the whole crank.

Not to hijack Latitude65's thread - Bluesdog - I well remember shifting the old friction shifters and how you had to shift and kind of pedal together followed by fine tuning the derailleur so it would not make any noise. I tried doing kind of the same thing with the pedals - to no avail. I agree with Latitude65 - there is a problem with the chainring or at least the mechanics at my lbs make noises like the same thing Latitude65 is hearing from his contacts.

John E

No, keep pedaling while shifting, but without applying any significant torque on the crank or driving force along the chain. You should be pedaling more slowly than if you were actually propelling the bike forward. To do this on hills, one has to anticipate downshifts, changing down to a lower gear before one's crank RPMs drop too low.

ModeratedUser150120149

Yes, please let me know how you make out. Since my bike is second hand there is no warranty on it that I'm aware of. Still, changing just the ring would, as you say, be less expensive than the whole crank.

ModeratedUser150120149

In other words; shift as I normally do, not pause as the LBS in CO says is normal. Thanks for the affirmation. Guess the next step is to wait for what I find out from Adriant about just changing the large ring gear.

'47

I can recall the nuances of shifting "back in the day" of the late 70's and early 80's where finesse was required for overshifting, avoiding too much chain tension when shifting down to prevent chain throw, etc. Having just returned t cycling, I marvel at the sloppiness that modern drivetrains allow. I slam the chain around out of the saddle, shift down under all kinds of tension w/o chain suck, etc. Components seem to hold adjustments better and longer...and are far more sophisticated and, not so good, complicated. Brand and sometimes gruppo dedication seems limiting in terms of interesting combinations of components one can't think up.

Overall, nice to recall the quaintness of old stuff, but there was nothing marvelous about friction shifting or climbing hills with a 5 cog freewheel. Yet I smile to recall what heroic things local riders did on that old, seemingly limiting stuff.

Sorry for meandering OT.

AdrianL

Lat-65

The lbs has ordered a new Ultegra chainring. It will be in on Tuesday or Wednesday of next week. I will give you a report immediately afterwards because I will try it at the shop.

It looks like you can get a new chainring for about $50 to $60. That's a lot better that $175 to $200 for a crankset.

ModeratedUser150120149

I'll look forward to a report on final cost and whether it solved your problem.

By the way; why did you pick Ultegra rather than say 105?

AdrianL

I did not "pick" the Ultegra. It's a warranty thing. The bike shop chose to replace the chainring with the Ultegra ring. I'm not complaining.

I would have probably picked the Dura Ace ring if I were able to pick. Not that there is anything wrong with either the 105 or the Ultegra. I've got Ultegra brifters and derailleurs so it kind of fits, I guess.

Actually, I suspect about the only difference between the 105, the Ultegra, and the Dura Ace is the material they are made of. Each is a little lighter than the one before. Perhaps one of the more knowledgeable people here could comment about this.

ModeratedUser150120149

Thanks.

It will be good to read how it works out.

ModeratedUser150120149

I just received a reply to my inquiry to Trek asking about this problem. The Trek Person seems to say that this is normal and if I want better shifting I need to "upgrade" the crank. I've asked for clarification. But, his answer seems to support my bike shop tech's opinion.

Maybe that is why Trek changed the crank between the 2007 and 2008 model years?

.