Help. How can I shorten my Q-Factor

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geeo123
Posts: 7
Joined: Thu Aug 06, 2020 8:38 pm

by geeo123

Hello, Sorry if this is confusing!

I have just ordered a Canyon Exceed.

I am pretty sensitive to a larger q-factor being a roadie. Can you guys please help me think of a way to reduce this as much as possible?
I usually ride an Ultegra road crankset with (148MM Q-Factor) and +54MM pedals so = 256MM in total.

The Canyon comes with a Shimano SLX M7120 (178MM Q-Factor) with a 55MM recommend chainline.
I havent bought any pedals yet. PLUS I need to switch to a shorted crank length (Switching to 165MM cranks). Hopfully these two factors is where we can do the magic.

There is also room for me to push my cleats all the way to one side, which should reduce it by around 10MM in total (5MM each side).

Would really appreciate any help, thank you!

George
Last edited by geeo123 on Fri Feb 17, 2023 3:21 pm, edited 2 times in total.

by Weenie


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hartox
Posts: 44
Joined: Mon Jan 23, 2017 11:44 am
Location: Netherlands

by hartox

Isn't it 254mm for 2 pedals?

geeo123
Posts: 7
Joined: Thu Aug 06, 2020 8:38 pm

by geeo123

hartox wrote:
Fri Feb 17, 2023 3:03 pm
Isn't it 254mm for 2 pedals?
Correct, edited above.

hartox
Posts: 44
Joined: Mon Jan 23, 2017 11:44 am
Location: Netherlands

by hartox

:lol:

The problem is you have to clear the chainstays (with your chainring and shoes), so it depends how narrow you can go. You could swap your crankset for a Rotor Kapic (Q-Factor: 164 mm / 170mm boost).

edit: The older Rotor Rex is even narrower (also for boost): Q-Factor: 163mm)

Hexsense
Posts: 3356
Joined: Wed Dec 30, 2015 12:41 am
Location: USA

by Hexsense

1) Pedal.
Use Shimano XTR PD-M9100 S1 Short axle pedal. The S1 (short axle) is 3mm shorter each side than standard (52mm vs 55mm). Giving you 6mm total narrower Q factor than standard pedals. Also, it has pretty big flange built in to the axle next to pedal thead. So, you can skip pedal washer when using carbon crank without causing damage. Most pedal washer are ~1mm and you don't need it with this pedal.

2) Crank.
Guarantee fit one would be: Sram X01 dub, 168mm. Buy standard axle length, not wide crank. MTB DUB wide isn't narrow...
55mm chainline is achieved via chainring offset. Use 0mm for 55mm offset instead of -3mm offset for 52mm.

I'm not so sure about Rotor Kapic 's fit with various optional axles.. They list q-factor as 164, 170. 164mm for non boost, 170mm for boost. If that's true. You need the boost one which it end up wider than Sram X01 carbon. Source: https://www.bike24.com/p2283189.html?sku=989602

geeo123
Posts: 7
Joined: Thu Aug 06, 2020 8:38 pm

by geeo123

Hexsense wrote:
Fri Feb 17, 2023 4:58 pm
1) Pedal.
Use Shimano XTR PD-M9100 S1 Short axle pedal. The S1 (short axle) is 3mm shorter each side than standard (52mm vs 55mm). Giving you 6mm total narrower Q factor than standard pedals. Also, it has pretty big flange built in to the axle next to pedal thead. So, you can skip pedal washer when using carbon crank without causing damage. Most pedal washer are ~1mm and you don't need it with this pedal.

2) Crank.
Guarantee fit one would be: Sram X01 dub, 168mm. Buy standard axle length, not wide crank. MTB DUB wide isn't narrow...
55mm chainline is achieved via chainring offset. Use 0mm for 55mm offset instead of -3mm offset for 52mm.

I'm not so sure about Rotor Kapic 's fit with various optional axles.. They list q-factor as 164, 170. 164mm for non boost, 170mm for boost. If that's true. You need the boost one which it end up wider than Sram X01 carbon. Source: https://www.bike24.com/p2283189.html?sku=989602
Thanks Both!

I think those pedals are a good shout.

If I was to buy a crankset with a 52mm chainline compared to the 55mm, do you reckon that would work? Shimano drop -6mm in Q-Factor between them.

Cheers

Hexsense
Posts: 3356
Joined: Wed Dec 30, 2015 12:41 am
Location: USA

by Hexsense

If the frame require 55mm chainline crank.

Shimano: You just can't use the narrow FC-M9100. You need wide version Shimano crank (FC-M9125-1 or FC-M9130-1) to get proper chainline for your frame. Shimano change chainline via longer axle. As a result, your q-factor isn't narrower than Sram anymore.

Sram: You can buy normal version Sram and change just the chainring from 3mm offset to 0mm offset. Sram change between 52 and 55mm chainline via chainring offset. No axle change, so Q-factor is maintained. There's still Sram Dub Wide (56.5mm chainline) for really wide mtb though. Like fat bike. Those have longer axle, thus wider q factor which you don't want.

zscs
Posts: 143
Joined: Thu Jul 26, 2018 12:05 pm
Location: Hungary

by zscs

2nd option is a good idea and sounds feasible. However, make sure that the missing 6mm from the axle length won't cause the cranks hit the chainstays. ;)

snaxez
Posts: 326
Joined: Fri Jun 06, 2014 7:14 pm
Location: Estonia

by snaxez

Hexsense wrote:
Fri Feb 17, 2023 9:59 pm
If the frame require 55mm chainline crank.

Shimano: You just can't use the narrow FC-M9100. You need wide version Shimano crank (FC-M9125-1 or FC-M9130-1) to get proper chainline for your frame. Shimano change chainline via longer axle. As a result, your q-factor isn't narrower than Sram anymore.

Sram: You can buy normal version Sram and change just the chainring from 3mm offset to 0mm offset. Sram change between 52 and 55mm chainline via chainring offset. No axle change, so Q-factor is maintained. There's still Sram Dub Wide (56.5mm chainline) for really wide mtb though. Like fat bike. Those have longer axle, thus wider q factor which you don't want.
Except with 8bolt SRAM has different XX1 crank for 55mm chainline. I suppose it`s mostly for Quarq.

Hexsense
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Joined: Wed Dec 30, 2015 12:41 am
Location: USA

by Hexsense

snaxez wrote:
Mon Feb 20, 2023 8:27 am
Except with 8bolt SRAM has different XX1 crank for 55mm chainline. I suppose it`s mostly for Quarq.
I rechecked the current catalog and I see 4 versions of X01 now. There used to be less...:
Sram X01 Dub. Q-factor 168mm. 49mm chainline via 6mm offset chainring. 52mm chainline via 3mm offset chainring. 55mm chainline via 0mm offset chainring.
Sram X01 Dub 55 CL. Q-factor 174mm. 55mm chainline via 3mm offset chainring. <- not sure when this one shows up.
Sram X01 Dub SB+. Q-factor 176.8mm 56.5mm chainline via 3mm offset chainring.
Sram X01 Fat bike. Q-factor 203.3mm. Lets just not considering this one.

Quarq spider have 3mm offset chainline built in.
It seems 55 CL version is for bikes that have wide bottom bracket or need 55mm chainline and want to use Quarq. If it's just the clearance, regular Sram X01 Dub with 0mm offset chainring have the same clearance at the chainring.

Also off topic info: why I recommend X01 and not XX1 to OP?
Regular XX1 3 bolt are no longer produced in 165mm length. 8 bolt version still offered in 165mm length. X01 are offered in 165mm length in both standard and wide version with 3 bolt mount.

Vik61
Posts: 65
Joined: Sat Sep 03, 2016 5:55 am
Location: Russia

by Vik61

Perhaps, you can use Sram Force Wide cranks. Same axle width to mtb, much more narrow q-factor. If you have enough frame space
Canyon Grizl
Trek Supercaliber

satanas
Posts: 370
Joined: Sat Jul 04, 2020 5:45 pm

by satanas

The chances of a SRAM Wide gravel crank clearing the chainstays on any post-2000 MTB frame are near zero; the Q factor is 150mm, versus 178mm for the original cranks. Not that many MTBs will clear the 162mm Q M9100 XTR cranks, or anything else less than ~168mm. There are few - if any - current MTB cranks with a Q less than 162mm. (Why MTB frame and crank designers don't care about this is a mystery to me - maybe just laziness?)

Re pedals: "Standard" Q is typically ~55mm, but less is possible:

52mm: XTR short spindle, Crank Bros, Garmin
47.9mm: SQlab 511 short

https://www.sq-lab.com/en/area-of-use/m ... attributes

Picking or having a suitable frame made is the first step here IMHO. Changing components can only go so far towards treating the original trauma inflicted.

Upcountry
Posts: 185
Joined: Mon Aug 07, 2023 10:59 pm

by Upcountry

satanas wrote:
Sat Dec 16, 2023 3:21 am
The chances of a SRAM Wide gravel crank clearing the chainstays on any post-2000 MTB frame are near zero; the Q factor is 150mm, versus 178mm for the original cranks. Not that many MTBs will clear the 162mm Q M9100 XTR cranks, or anything else less than ~168mm. There are few - if any - current MTB cranks with a Q less than 162mm. (Why MTB frame and crank designers don't care about this is a mystery to me - maybe just laziness?)
This isn't entirely true... Limited sample size, but I'd imagine they'd fit more than people think, but its an expensive experiment, and you then have to order separate chainrings and such, so its a barrier most people aren't willing to jump over. I'm running a Sram Force Wide w/ Quarq spindle crankset on both my 2023 Epic Hardtail, as well as my 2022 S-Works Epic Evo... The clearance is tighter on the Epic Evo(~2.5mm versus nearly 4mm on the Epic HT), as expected wth the bulk and movement of the rear swing arms, but I've put several hundred miles on it without issue. I have put some helicopter tape on the chainstay to protect it in case. You have to keep in mind that although the Q-factor as measured at the pedal washer interface is only 150mm, the arms are slimmer than many out there, so you gain a few mm's on the back side when comparing to an XTR or similar. Chainline is really easy to adjust with tons of offerings in 0mm, 3mm, and 6mm offsets. The factory Sram Wide chainrings are like 8.5mm offset and won't clear much, in addition to their limited sizes(38t smallest maybe?).

Image

satanas
Posts: 370
Joined: Sat Jul 04, 2020 5:45 pm

by satanas

Good to know - thank you!

I can see I need to start measuring chainstay widths...

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F45
Posts: 1081
Joined: Wed Jun 08, 2011 6:08 am

by F45

The old M9000 cranks had a version with 158mm Q factor. Pivot's website said they wouldn't work but they fit fine on the bike. Not sure if you could get the correct chainline though.

I ended up selling them because of lack of control on the descents. Went to the 174mm trail versions. Much better.

by Weenie


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