Cervélo R5 2015-2017 gen - size opinion

Discuss light weight issues concerning road bikes & parts.
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machadok1
Posts: 14
Joined: Sun Jul 09, 2017 1:30 pm

by machadok1

Hi,

About 5 months ago, I bought a Cervélo R5 (2015-2017). My height is 1.81-1.82 m and my flexibility is bad, despite this, I am a reasonable cyclist. When I went to buy it I went with the idea of ​​size 54. However, the seller always advised me to go to 56 and did a retul bikefit in that same store that indicated that size. I ended up buying the recommended bike -size 56- with a 100 mm stem and 10 mm spacer; my saddle height is 77 mm (85 inseam) and I use a 0 offset seatpost with the saddle in the middle.
I tend to ride regularly, about 4 times a week both long rides of 100 km with 1500-1700 uphill 26-28 km/h average and short but fast rides (my fastest time in a circuit with 30 km and 320 of uphill alone was 36 km/h with this bike). However, I do not feel perfectly fit on the bike and after reading some things here, I started to think that maybe it would be better to have gone to the 54 with a bigger stem and some spacers. Do you think I should try to change the frame or this size is suitable for my height?

russianbear
Posts: 757
Joined: Wed Apr 11, 2012 3:40 am

by russianbear

The only thing getting a 54 would get you is a longer stem, more spacers (yuck) and a lighter wallet. Listen to your fitter and not to people on the internet.

by Weenie


964Cup
Posts: 191
Joined: Tue Dec 18, 2012 1:31 am

by 964Cup

Hard to say for sure unless you can explain in what way you feel uncomfortable, but better advice would be to look again at frame geometry. A smaller R5 will reduce both reach and stack, and in fact stack considerably more (-25mm) than reach (-9mm). This won't help you if flexibility is an issue. Maybe you need a more endurance-orientated frame - like an RS or a C5 in Cervelo terms, or something like a Domane. It sounds like you need a shorter reach but the same or more stack. Another thing to look at would be shorter reach bars (say Zipp SL70) to bring the hoods closer in; if you're running a zero-offset post on a frame normally shipped with a 25mm layback, that suggests you're over-stretched. Bringing the saddle forward given your height may have given you less than perfect biodynamics with reference to the pedal circle; you don't mention crank length.

For reference, I ride a 56 Cervelo (I have an R5VWD, R5Ca and S5); I'm 1m86, run a 79cm saddle height with a 175 crank and an 86.5cm (cycling) inseam, 72cm to the hood centreline from the saddle tip (75cm diagonal, 42cm bar), and a 5mm spacer.

clipsed
Posts: 61
Joined: Wed Feb 04, 2015 12:48 pm

by clipsed

I also have a 77cm saddle height with a zero offset post on a 56cm frame with similar geo to an R5.

From what you describe, i wouldn't go 54.

I run 10mm spaces with a 130mm stem (long arms and legs) and i am 177cm tall.

machadok1
Posts: 14
Joined: Sun Jul 09, 2017 1:30 pm

by machadok1

Hello
Thank you all for the answers.
I don't have any pain; my main problem is some instability in front of the bike (probably due the short stem for the size). When I choosed this frame, I looked for the more "relaxed" in those considered "racing"; there were others I also liked - supersix evo and tarmac - however, given the more aggressive geometry I opted for R5. Now I don't not know is if I choosed the right size that makes the best compromise. The components were chosen before buying the bike based on the fit - the handlebar is a 3T Ergosum LTD. I'm training to improve flexibility a little bit because I am still young (24 years old), so in the future it's more likely to put a 110 mm stem and take off the 10 mm spacer, for example, than sustain handlebar drop in the size 54 (or I will always have spacer tower and lots of exposed seatpost)?...I say this because looks also counts and this was the 1st excellent bicycle that I bought and I want to keep it for life. Despite this, n+1 bikes always checked. :D

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silvalis
Posts: 387
Joined: Mon Sep 07, 2015 1:02 am
Location: Aus

by silvalis

100mm isn't really short for a 56cm frame. Maybe 10mm shorter than normal, but not short enough to make it feel unstable...

wingguy
Posts: 3951
Joined: Thu Mar 08, 2012 11:43 pm

by wingguy

Yeah. 100mm isn't particularly short for a 56cm frame, especially since the Ergosum is a very long reach handlebar by modern standards. Approximate equivalent of running a 120 stem with a Zipp SL70 bar, for instance. It may also be narrower than you think, most 3T bars are measured at the drops and are 2cm narrower at the hoods. I personally like narrow bars, but wider ones are naturally more stable for high speeds and cornering.

Also, flexibility is hugely overrated as a governing factor of riding position, IMO. Core conditioning and overall weight/fitness are more likely to be the limits. If you're 24 and not fat there's no reason you can't sustain very good race position, assuming that's what you want (in fact, with what I'm figuring is around 10cm of drop and a reasonable overall reach it's quite aggresive already).

Suggestions would be that any handling problems are probably more down to you than the bike (sorry) but for sure put on a 110mm stem and see how it feels. No reason it should cost more than £15 for one to experiment with instead of jumping straight into a buying another frame that is further away from what is conventional for your height.

GothicCastle
Posts: 114
Joined: Mon Jul 04, 2016 1:52 am

by GothicCastle

machadok1 wrote:My height is 1.81-1.82 m and my flexibility is bad, despite this, I am a reasonable cyclist. When I went to buy it I went with the idea of ​​size 54. However, the seller always advised me to go to 56 and did a retul bikefit in that same store that indicated that size. I ended up buying the recommended bike -size 56- with a 100 mm stem and 10 mm spacer; my saddle height is 77 mm (85 inseam) and I use a 0 offset seatpost with the saddle in the middle.
Based solely on your dimensions, it seems like your torso is a bit proportionally short and that you are right in between a 54 and 56. In that case, I’d choose the smaller size as it is easier to make the bike longer and taller than vice versa.

I’m having a little trouble reconciling that with the dimensions of this frame, though. The 56 is only about 1 cm longer than the 54, but it is nearly 2.5 cm higher. That difference wouldn’t result in a much longer stem (and I wouldn’t expect a 100mm stem to make the bike feel terribly twitchy). I suspect that you should try to get more weight over the rear wheel, but that is a guess.

Getting fitting advice over the internet is dangerous, as the fitter you consulted had the benefit of watching you ride the bike.

machadok1
Posts: 14
Joined: Sun Jul 09, 2017 1:30 pm

by machadok1

First of all, thank you all for your opinions :)

@wingguy and @GothicCastle - I'm not fat, I'm 74 kg :D and probably yes, the handling problems are also my fault. I looked for some adjustments in the bike and I verified that the KOPS is verified; however my bikefitter put the cleats in a more back position on the shoes, hence the zero offset seatpost ( combined with my saddle height). I'm not stretched out on the bike and so I have two options: to advance the cleats a bit (it does not seem very reasonable since I feel good like this - I'm using Sidi wire shoes with shimano yellow cleats) and consequently to push back the saddle in order to maintain the other angles. Another try may be using a bigger stem and this is where I'm going to start with a 110 mm as you said.
@GothicCastle - The differences between the reach are 0.9 cm; however the actual difference is 1.6 cm (equal to the difference in the ETT) because the seat angle is the same and the difference is due to the HT angle and the stack difference. With 25 mm of spacers in size 54 I have less 1.6 cm of reach and equal stack. It's not like this?

wingguy
Posts: 3951
Joined: Thu Mar 08, 2012 11:43 pm

by wingguy

machadok1 wrote:I looked for some adjustments in the bike and I verified that the KOPS is verified; however my bikefitter put the cleats in a more back position on the shoes, hence the zero offset seatpost ( combined with my saddle height). I'm not stretched out on the bike and so I have two options: to advance the cleats a bit (it does not seem very reasonable since I feel good like this - I'm using Sidi wire shoes with shimano yellow cleats) and consequently to push back the saddle in order to maintain the other angles.
KOPS is overrated IMO, a guideline maybe but def not a rule. A zero offset post is unusual for your height. Not neccessarily wrong, but your weight distribution on the bike probably isn't quite normal. Personally I'd try wacking the saddle back a bit and see what happens but that's totally up to you.
@GothicCastle - The differences between the reach are 0.9 cm; however the actual difference is 1.6 cm (equal to the difference in the ETT) because the seat angle is the same and the difference is due to the HT angle and the stack difference. With 25 mm of spacers in size 54 I have less 1.6 cm of reach and equal stack. It's not like this?
Good point, and easy to overlook. Yes it is like that.

machadok1
Posts: 14
Joined: Sun Jul 09, 2017 1:30 pm

by machadok1

wingguy wrote: KOPS is overrated IMO, a guideline maybe but def not a rule. A zero offset post is unusual for your height. Not neccessarily wrong, but your weight distribution on the bike probably isn't quite normal. Personally I'd try wacking the saddle back a bit and see what happens but that's totally up to you.
The correct use of the setback is related to the seat tube angle and saddle height, right? This frame uses 73º for all sizes instead of decreasing it with the increase of frame size.The higher the inseam, the higher the seatpost and the more backward will be relative to BB, so does not use to compensate for this?

istigatrice
Posts: 802
Joined: Sat May 12, 2012 8:32 am
Location: Australia

by istigatrice

just check that the fork which was supplied is the correct rake fork. AFAIK Cervelo have two different fork rakes, and if the fork for the smaller sizes was supplied with a larger size it could result in twitchy handling.

Otherwise if the fork is correct it's probably just you.
I write the weightweenies blog, hope you like it :)

Disclosure: I'm sponsored by Velocite, but I do give my honest opinion about them (I'm endorsed to race their bikes, not say nice things about them)

Aya
Posts: 41
Joined: Sun Dec 17, 2017 11:50 am

by Aya

I'm 179cm tall, my inseam is 84cm and I ride 2016 R5 54 size which have spacers of 15mm. I set my saddle height about 74cm. I've checked distance from the top of the saddle to the handlbar some days ago which was 8cm. When I went to the shop for buying R5, the dealer said both 54 and 56 would fit me well. It seems your inseam length is similar to mine so I guess you can ride 54 either, but your saddle height is quite higher than mine. If you really set your saddle height to 77cm, I recommend a 56 size frame.

by Weenie


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