F4 MTB Drive Train Recommendations

[JohnnyD]

crank arm length isn't really 100% tied to rider size. If you ride your current bike comfortably with 170mm then I would stick to that. There is an leverage advantage to the longer crank arm when power to applied during pedalling, but honestly. I used 170mm crank arms on my Jekyll and didn't feel any different pedaling that bike than I did on my M700 with it's 175mm crank arms. Nor did it feel any different with the new(used) carbon fiber Race Face 175mm crank that I installed yesterday on it.
That's based on my "seat of the pants" feelings while riding though.

 

[black lightning 1987]

At under 5' I would think the 165 mm crank would be appropriate.

 

[JohnnyD]

That's the challenge of buying a bike used, which if I recall she said she did a long while ago. If not then then the LBS that sold her it didn't do a good job of fitting the bike to her size. I would havedsuggested she call World Wide Cyclery about it, but the 165 mm version crankset she ordered is out of stock. Thankfully she ordered the 170 mm, which is what the bike has on it now. If she is comfortable riding her bike now with that length then she will still feel the same. Ideally, 165 mm would have been much more optimal with a smaller frame. I think she said it was a small, She's mentioned that she has very little stand over distance on the top tube and the Petite of that year only had 1/2" shorter height.
AHH the frustrating joys of trying to help someone.

Edit: It 5 mm shorter not 1/2 inch!

 

[black lightning 1987]

I thought she might also gain a bit of toe overlap clearance, which may or may not be an issue currently. 5 mm is not much but might be just enough in certain situations.

 

[JohnnyD]

You're right about 5 mm not seeming like much. As you know, those tiny distances make a HUGE difference in rider comfort. For instance, look how much riding with a super high seat position makes a difference for you. Whereas, it makes me feel like I am going to fall off the bike.

 

[BethZ]

That's the challenge of buying a bike used, which if I recall she said she did a long while ago. If not then then the LBS that sold her it didn't do a good job of fitting the bike to her size. I would havedsuggested she call World Wide Cyclery about it, but the 165 mm version crankset she ordered is out of stock. Thankfully she ordered the 170 mm, which is what the bike has on it now. If she is comfortable riding her bike now with that length then she will still feel the same. Ideally, 165 mm would have been much more optimal with a smaller frame. I think she said it was a small, She's mentioned that she has very little stand over distance on the top tube and the Petite of that year only had 1/2" shorter height.
AHH the frustrating joys of trying to help someone.

Edit: It 5 mm shorter not 1/2 inch!

Aw, I don't mean to cause frustration. I know I ask a lot of questions - it's just how I learn! I bought the bike new. I don't think the F4 came in a petite size (only the F6). It's still a smaller frame size than any of the petite hard talils out there now - unless you get a step-through frame. I hear two different opinions on standover height. One bike shop person told me it's not important and some articles say the same. Then there are opinions that standover height is very important to safety. I just need to gain more confidence in stopping, standing and dismounting.

 

[JohnnyD]

Aw, I don't mean to cause frustration. I know I ask a lot of questions - it's just how I learn! I bought the bike new. I don't think the F4 came in a petite size (only the F6). It's still a smaller frame size than any of the petite hard talils out there now - unless you get a step-through frame. I hear two different opinions on standover height. One bike shop person told me it's not important and some articles say the same. Then there are opinions that standover height is very important to safety. I just need to gain more confidence in stopping, standing and dismounting.

You aren't causing anything. I am glad you ask questions, it helps me continue to improve my own knowledge so I can help others, or at least attempt too. As far how important stand over height is to you, well I think you answered that question best with your last sentence. The only way I know to gain confidence in learning an activity is to DO it again and again.. So once you get the drivetrain installed find the free time to get out and ride!

 

[BethZ]

I found an interesting article on Shimano vs. SRAM drive trains from this February. If anyone on these forums are interested - please pass it on!

Shimano vs. SRAM: Guide to Groupsets, Drivetrains, Brakes, and More

Choosing between Shimano and SRAM can seem like a big choice when shopping for bikes. We'll compare key tech highlights for each brand's drivetrains, brakes, and other components so you can make a more informed decision.

www.theproscloset.com

 

[JohnnyD]

Thanks for the link. Although, I feel it is worth mentioning the SRAM is finally releasing a mineral oil based hydraulic disc brake called the DB8. From SRAM's own marketing text is it basically a SRAM Code model brake that has been converted to mineral oil. I thought about waiting for these brakes to be released for retail sale, but like most product launches these days. It is a "paper" launch... or in the IT world.. vapor ware.

 

[BethZ]

Well, I got my bike back from the shop, new drive train installed and it's amazing! No problem with peddling uphill and the bike just feels great. The only thing is after the 3rd ride, the gears seem to be slipping and not shifting smoothly. Possible needs the tension adjusted, which I will do and report back. I do have to bring it back to have the fix a stupid little thing they did. They zipped tied the shifter cable to my bike rack instead of running it straight to the derailleur (you'll see in the picture).

 

[JohnnyD]

OMG The bike looks great!!!!!The blue Jagwire cables and brake housings make it even better. I agree that I think it was silly of them to route the shifter cable to the derailleur like that.It should be a straight as possible. The derailleur wont move as much as they have given you slack for. Have give it a nice gentle arch with about a 1/2 inch up or down and it will be fine.. Also, from what you said I also think that you are right on it needing to have the cable tension adjusted. If they didn't ride it after setting it up, it's very easy to get it really close but it still needs to be fine tuned while riding. I had to turn the adjustment about a quarter turn to get mine dialed in just right.

As a final note. I told you that you'd love how much easier it is to ride with as much gear range as the 11-50T cassette has.

 

[black lightning 1987]

Looks like the rear section of housing could be shortened by 2 or 3 inches, but I have no experience with SRAM post 10 speed.

Sounds like it will be good once the final adjustments are made and the bike looks great. Glad Johnny was around to make recommendations on this newfangled stuff.