Best Frame Size and Crank Length for Short Inseam

bernithebiker

As I'm hiring a bike for a few days in Majorca next week (a Canyon), I went to their sizing section and it turns out they think I have a freakishly short inseam (75cm) for my height (174cm).
The bike size they suggest is XS (50), whereas i ride an M, 54 .(SL4). Crank size was 165 to 170mm.

Bit of a shocker, as I've always been comfortable on the SL4, and I have a 120mm stem fitted, and even then the cockpit feels a bit small. Even allowing for some error by Canyon, it suggests I should be on a 52.

I went from 175 to 172.5 to 170 cranks over the last few years, and am happy with 170's, but now wondering if 165's would be even better for my small legs.

What are the downsides? I see only ups;

1. Less knee/joint strain.
2. Easier to maintain high cadence.
3. Easier to get aero.
4. Easier to pedal circles (controversial this one!)
5. Better ground clearance.
6. Lighter!

drlodge

Suggest you find out what bikes they rent, find the geometry and compare top tube lengths with your bike.

Your inseam is 29.5", not massively short I'd say just less than average. Think Medium is a tad big, probably a small frame is better. But it all comes back to geometry.

As for crank length - if you feel fine on 170s stick with them.

bernithebiker

I'll be hiring a 52 (S/M) as that's all they've got anyway, but it'll be interesting to feel any difference.

Always in the quest for marginal gains!, even though the 170's feel good, would 165's be better? Trouble is I'd have to spend £200+ to find out…..I tend to think the potential gains outweigh the pitfalls though.

The main question will arise when the SL5 comes out later this year, and if I can afford it, do I go 54 or 52?

florerider

Bernie

same inseam as you, maybe a cm taller than you. Have 2 bikes, both 54 sizes with 545mm T/T. Originally ran them with 80mm stems - but found both to be too cramped so went to 100mm stems, made a vast difference to comfort.

Had been thinking about 110 or 120 stems too, want to get lower but by going longer rather than down.

Be interested to hear back on what you find on the smaller frame.

bernithebiker

florerider wrote:

Bernie

same inseam as you, maybe a cm taller than you. Have 2 bikes, both 54 sizes with 545mm T/T. Originally ran them with 80mm stems - but found both to be too cramped so went to 100mm stems, made a vast difference to comfort.

Had been thinking about 110 or 120 stems too, want to get lower but by going longer rather than down.

Be interested to hear back on what you find on the smaller frame.

Good to hear I'm not the only one that Canyon considers a 'freak'! (They said I should have an inseam of at least 82!)

My wife is now calling me a hobbit.

The only way I could get my SL4 as low at the front as my old Trek was to use a -17' 120mm stem (135mm headtube, versus 118 or 120 I think). So I am low and long, but I quite like it like that.

Not sure what kind of stem the Canyon will have; I suspect I will have to remove some spacers! Pick it up on Monday in Palma, will report back!

matt-h

Hi Bernie,
I am 178cm with a 79 inside leg.
I run a 54 med and was recommended by the Retul bike fitter that if buying a new bike to get a smaller frame.
I now run 165 cranks over my previous 172.5 and the fitter has noticed a better line in my knees.
My cadence is up a little and I have no knee pain in the slightest.

Matt

bernithebiker

Had 2 rides out here on the Canyon 52 so far.

Doesn't feel small at all, despite having a short stem (80mm I think).

Took off all the spacers and had to rotate the bars to drop the hoods, and it still feels high to me. Would need a 100mm stem at least to be comfy.

I took my saddle and post along with me and fitted that, and I've only had to raise the post 5mm compared to my bike.

170mm cranks, same as mine.

So overall feels fine to ride, if not as light or reactive as the SL4 (the wheels probably count for a lot there, Kysriums versus Meilensteins), so if I do go for an SL5, most likely it'll be a 52. Might consider getting 165 cranks for it.

ai_1

bernithebiker wrote:

Had 2 rides out here on the Canyon 52 so far.

Doesn't feel small at all, despite having a short stem (80mm I think).

Took off all the spacers and had to rotate the bars to drop the hoods, and it still feels high to me. Would need a 100mm stem at least to be comfy.

I took my saddle and post along with me and fitted that, and I've only had to raise the post 5mm compared to my bike.

170mm cranks, same as mine.

So overall feels fine to ride, if not as light or reactive as the SL4 (the wheels probably count for a lot there, Kysriums versus Meilensteins), so if I do go for an SL5, most likely it'll be a 52. Might consider getting 165 cranks for it.

Which model of Canyon are you on?

bernithebiker

I'ts a CF SL with Ultegra and Kysrium wheels.

ai_1

bernithebiker wrote:

I'ts a CF SL with Ultegra and Kysrium wheels.

Just curious since you said it wasn't as light or reactive as your SL4. I would have thought either the CF Ultimate SL or SLX would give the SL4 a run for it's money. Perhaps the wheels are a factor as you say.

The Canyon CF Ultimate headtube lengths are not super aggressive and the Acros headset adds a bit more to the height. Having said that it's not a relaxed geometry either - somewhere in the middle really which suits me. The good news is that Canyon consider me pretty normal at 1.78m and 83.5cm inseam

bernithebiker

i think its really the wheels and the fact that my SL4 is probably almost 2kg lighter, coupled with the lower front end.

If I built up this Canyon with all my SL4 bits, I doubt I'd notice a difference.

Lifeboy123

Ive just come back from Mallorca
I'm 5'8, 30 inside leg and ride a 54 Madone , 53 boardman both sizes advised by several bike shops before buying.
I Hired a Cannodale Evo6, had to take a 50 as there were no 52s left, other than needing a slightly longer stem, the smaller size was very comfortable and a lovely bike to ride

ai_1

bernithebiker wrote:

i think its really the wheels and the fact that my SL4 is probably almost 2kg lighter, coupled with the lower front end.

If I built up this Canyon with all my SL4 bits, I doubt I'd notice a difference.

The Canyon weighs just under 7kg. Surely your SL4 is far heavier than 5kg?

bernithebiker

Ai_1 wrote:

bernithebiker wrote:

i think its really the wheels and the fact that my SL4 is probably almost 2kg lighter, coupled with the lower front end.

If I built up this Canyon with all my SL4 bits, I doubt I'd notice a difference.

The Canyon weighs just under 7kg. Surely your SL4 is far heavier than 5kg?

the SL4 is 5.9kg, but I was estimating the Canyon at about 8.

It's full Ultegra, but has quite a lot of heavy finishing kit on it, and it's also got things like chunky metal bottle cages, saddlebag, pump, etc. etc. Maybe it's around 7.5, but I'd be very surprised if it's below 7.

ai_1

bernithebiker wrote:

Ai_1 wrote:

bernithebiker wrote:

i think its really the wheels and the fact that my SL4 is probably almost 2kg lighter, coupled with the lower front end.

If I built up this Canyon with all my SL4 bits, I doubt I'd notice a difference.

The Canyon weighs just under 7kg. Surely your SL4 is far heavier than 5kg?

the SL4 is 5.9kg, but I was estimating the Canyon at about 8.

It's full Ultegra, but has quite a lot of heavy finishing kit on it, and it's also got things like chunky metal bottle cages, saddlebag, pump, etc. etc. Maybe it's around 7.5, but I'd be very surprised if it's below 7.

The Canyon CF SL 9.0 which is the new Ultegra version with Ksyrium Elites has a quoted weight of 6.95kg (for a M/54 I think). Mine is certainly very close to 7kg although my scales aren't accurate enough to say more than that. Including, pedals, cages etc, yours will be above 7kg.

bernithebiker

Quoted weights should always be taken with a pinch of salt, and of course pedals add 300g immediately.

So if you allow a fudge factor of 3%, then you have 7.2kg, + 300 = 7.5, + all the bits and bobs.

Anyway, I'm quite sensitive to bike weight, as I'm light myself, and therefore don't make masses of power, and in the eternal hunt for KOM's, I feel I may have had 1 or 2 more, had I had my own bike!

ai_1

bernithebiker wrote:

Quoted weights should always be taken with a pinch of salt, and of course pedals add 300g immediately.

So if you allow a fudge factor of 3%, then you have 7.2kg, + 300 = 7.5, + all the bits and bobs.

Anyway, I'm quite sensitive to bike weight, as I'm light myself, and therefore don't make masses of power, and in the eternal hunt for KOM's, I feel I may have had 1 or 2 more, had I had my own bike!

Not disagreeing with you re weight. Just surprised the SL4 was so light. 5.9kg including additional hardwear is VERY impressive.
Incidentally, the Canyons do seem to come in around the quoted weight from what I've seen with my own and from other reports.

bernithebiker

Ai_1 wrote:

bernithebiker wrote:

Quoted weights should always be taken with a pinch of salt, and of course pedals add 300g immediately.

So if you allow a fudge factor of 3%, then you have 7.2kg, + 300 = 7.5, + all the bits and bobs.

Anyway, I'm quite sensitive to bike weight, as I'm light myself, and therefore don't make masses of power, and in the eternal hunt for KOM's, I feel I may have had 1 or 2 more, had I had my own bike!

Not disagreeing with you re weight. Just surprised the SL4 was so light. 5.9kg including additional hardwear is VERY impressive.
Incidentally, the Canyons do seem to come in around the quoted weight from what I've seen with my own and from other reports.

Always been a bit of a weight weenie - I had a full sus Xcountry MTB back in 2001 that weighed 9.3kg!

The SL4 is full DA9000 with stuff like AX/Use seat combo that weighs less than 200g.

The Canyon's a nice bike - well made, and very beefy around the BB and head tube. Certainly not lacking in stiffness.