I know this question has been asked 1000 times on the internet and perhaps on these forums but every situation is different, no?
I'm getting chain slip on my road bike. Only happens under sprint power (for me, that's only like 500-ish), and only in big chainring/smallest cogs. I need help diagnosing this problem.
The chain and cassette are both new (chain new 2 months ago, only a couple hundred miles maybe, cassette new last week). Easy first culprits eliminated.
I have painstakingly ensured my RD is adjusted properly. Drivetrain makes absolutely no noise, shifts perfectly, and limit screws (particularly H, since happens on outermost cogs) are aligned. I do not think that is the issue.
System is: allez sprint disc, 105 R7000 RD, R8000 cassette, dura ace chain w/ Silca super secret, front rings are praxis 48/32.
So, possible culprits as far as my research leads me:
1. Freehub pawl engagement problem. I have not investigated this, I can, but since the issue is only produced in certain gears, as opposed to simply a certain power, can this be eliminated? My sense is that if 500W makes it skip, the 500W force on the freehub should produce the issue no matter what gear it's in, if that is where the problem lies.
2. RD hanger/pulley is bent. This seems to be a reasonable culprit. The RD is old-ish (105 R7000, total mileage unknown but probably at least 7000 mi). However, again the drivetrain is perfectly silent and performs 100% flawlessly in terms of shifting, so these part(s) being bent only makes partial sense. Is it feasible that they'd only
3. Frame flex causes misalignment. Logically might make sense, but I'm no elite rider, the power where this happens is 500-ish watts, not 1500. And, the bike is a specialized allez sprint disc which everyone says is stiff as all heck, so I don't think this makes sense to be the culprit.
4. Crack in the frame. Again, unlikely but I can't dismiss the possibility. I've inspected every inch of the lower triangle, no evidence of crack. since the frame is aluminum, anyone have any handy tips on how to search for cracks? I imagine if this was the case i'd hear worse noises or have other symptoms while riding besides chain slip.
5. something with the front chainring - internet indicates this can cause rear slippage, but i'm not sure how? in any event, the teeth are not worn, and while ring is a non-standard 48t, people run that type of size or smaller all the time with 1x setups and it's only 2t away from standard 50, so I wasn't thinking the problem is up front but maybe i'm missing something.
Before I sink a bunch of money into this, wanted to consult the wisdom that be ST. I know a new RD or RD hanger as a first step isn't a ton of money, but want to make sure I'm thinking straight before I go down the rabbit hole of what to spend on to diagnose and fix this.
I'm getting chain slip on my road bike. Only happens under sprint power (for me, that's only like 500-ish), and only in big chainring/smallest cogs. I need help diagnosing this problem.
The chain and cassette are both new (chain new 2 months ago, only a couple hundred miles maybe, cassette new last week). Easy first culprits eliminated.
I have painstakingly ensured my RD is adjusted properly. Drivetrain makes absolutely no noise, shifts perfectly, and limit screws (particularly H, since happens on outermost cogs) are aligned. I do not think that is the issue.
System is: allez sprint disc, 105 R7000 RD, R8000 cassette, dura ace chain w/ Silca super secret, front rings are praxis 48/32.
So, possible culprits as far as my research leads me:
1. Freehub pawl engagement problem. I have not investigated this, I can, but since the issue is only produced in certain gears, as opposed to simply a certain power, can this be eliminated? My sense is that if 500W makes it skip, the 500W force on the freehub should produce the issue no matter what gear it's in, if that is where the problem lies.
2. RD hanger/pulley is bent. This seems to be a reasonable culprit. The RD is old-ish (105 R7000, total mileage unknown but probably at least 7000 mi). However, again the drivetrain is perfectly silent and performs 100% flawlessly in terms of shifting, so these part(s) being bent only makes partial sense. Is it feasible that they'd only
3. Frame flex causes misalignment. Logically might make sense, but I'm no elite rider, the power where this happens is 500-ish watts, not 1500. And, the bike is a specialized allez sprint disc which everyone says is stiff as all heck, so I don't think this makes sense to be the culprit.
4. Crack in the frame. Again, unlikely but I can't dismiss the possibility. I've inspected every inch of the lower triangle, no evidence of crack. since the frame is aluminum, anyone have any handy tips on how to search for cracks? I imagine if this was the case i'd hear worse noises or have other symptoms while riding besides chain slip.
5. something with the front chainring - internet indicates this can cause rear slippage, but i'm not sure how? in any event, the teeth are not worn, and while ring is a non-standard 48t, people run that type of size or smaller all the time with 1x setups and it's only 2t away from standard 50, so I wasn't thinking the problem is up front but maybe i'm missing something.
Before I sink a bunch of money into this, wanted to consult the wisdom that be ST. I know a new RD or RD hanger as a first step isn't a ton of money, but want to make sure I'm thinking straight before I go down the rabbit hole of what to spend on to diagnose and fix this.