[Closed] Road bike sizing

I felt like I wanted to get further back on the seat so we took the post up higher to within 40mm of minimum insert.

A saddle is at the right height or it isn't that shouldn't be how you are trying to sort out a fore and aft position.

So on your post i'd say you don't have enough information do make anything other than a guess.

As the seat post goes up it goes back as well, it's not got a vertical seat tube.

As the seat post goes up it goes back as well, it’s not got a vertical seat tube.

But the saddle still needs to be at the correct height for pedalling. You can't just raise it to move the saddle further back unless you're inspector gadget.

Well seeing as my last post got so warmly received ...

... I think you need to read up on how bikes fit you.

Legs are a set length. The saddle position in terms height and fore and aft is to do with your leg length and upper leg length respectively they aren't ajustments for making a bike fit you*

I mean they obviously are but they're really for making the right size bike fit your specific geometry. Once these are set THEN you can work out if the bike fits you in terms of reaching bars and stuff which you adjust with stem length and spacers.

There might be some tweeking as everthing fits into place/to get comfortable.

So for eg

I am 5.8 but i have quite long legs and arms.
I have quite alit if seat post showing on a medium frame because i need the frame to be short for my short torso. I also have quite long arms so the bars are pretty slammed. Its not a massively agressive position for me bug the bike looks like its a full bum up in the air job.

I could get the correct height with either medium or large, so I guess the extra reach of the large would be a benefit. Would you expect toe/wheel overlap on most road bikes? cheers

If you have problems with saddle positioning fore and aft going to a large won't solve the issue...the seat tube will be the same angle so for a given height from the BB the saddle position fore and aft will be the same. If you feel you want the saddle further back you need a layback seat post.

Thanks I think I've probably got the opposite problem with shorter legs and a longer torso. I'll see if I can find a large to throw a leg over. The Btwin was a good size although I did get a bit of hip pain if I did a full week of 30mile commutes, although that's now been halved.

I'd not be surprised by toe overlap but I couldn't tell you if mine did as its just one of things that happen s when stationary but never happens moving as you tend to lean more and don't turn the bars that much. Unless you're on a fixed gear where you can't control your foot position when turning tightly its a non issue.

Just to throw in a slight curve ball. Saddle height does impact on its fore aft position and your position.

At one extreme a Triathlon (non uci) position has the saddle a lot further forward and the seat post raised slightly, at the other extreme a bike for endurance bimbling(tm) would be much more upright, slacker seat angle and slightly lower seat height.

Not enough to worry frame/seatpost minimum insertion marks mind you. But yes, a bike with a taller stack measurement will feel best with the saddle further back than on an out and out race bike.

Looking at those geometry numbers I'd say go down on the reach measurement to a medium unless the triban either doesn't fit or you've had to adjust it freakishly out of the normal or deliberately made it more upright. So there's a lot of assumptions there.

I’d say toe overlap was undesirable

Just to throw in a slight curve ball. Saddle height does impact on its fore aft position and your position.

No curve ball totally agree i actually thought i'd put in that changing one would change the other.

But raising a saddle is not how you make it go backwards to make it fit.

JV has it. 5’10”, 32” inside leg? You’re a medium. Saddle height will be about 72-74cm and nose 5-7 cm behind the BB. Once you’ve set the saddle properly, you then adjust reach to fit properly. Longer body and shorter legs? Then you might want a longer reach, but go for a longer stem. Longer legs and shorter body? Only then might you size down.

When between sizes, size down with a longer stem for same reach. You’ll have more weight over the front wheel and the bike will handle better. Go big and the reverse applies, the bike will feel less planted and you’ll wander why it doesn’t handle like it’s on rails.

Thats a great point tired.

Riding a road bike without enough weight on the front can be terrifying!

I’d say toe overlap was undesirable

It's inevitable on most bikes smaller than ~58cm l/XL bikes.

Some bikes get round it by slackening the head angle and increasing the fork offset.

But tbh it's not a big deal except on a fixie. You can't realistically pedal with the bars turned at 30deg anyway.

Okay thanks for the advice, think I'll take the medium for a longer test ride and think about stem length.

It’s not even a big deal on fixed. I ride two and a half hours today on mine, fitted with mudguards. Didn’t give it a moments thought.

Buy the medium. Thank us later.

If you take a test ride ask them to swap stems as needed.

Toe overlap and sizing may be the least your worries riding this stunner in public

#Chickmagnet

😉

It’s inevitable on most bikes smaller than ~58cm l/XL bikes.

I ride a 52 Spesh Diverge, only have toe overlap with mudguards fitted. Mrs has a 48 Diverge, no problem.

Re. saddle, you can of course adjust it for and aft on the rails without raising the seatpost, though as wobbliscott says you can use a layback seat post if you need to get it further back.

@geex that's the good looking option the one I'm after is worse. Actually even worse in the flesh.