Giant Toughroad SLR1 - Seat post slipping - large rider!!

[jimboban]

Hi Guys

First time poster - looking for some advice - please tell me if I have posted this in the wrong section etc.

I won't bore you with the history, decided to take up some gentle cycling for health reasons - starting with a couple of miles a day and building up from there.

Having not cycled for over a decade, I needed to purchase a bike and engaged with my local store for some advice on what to go with - budget not a big issue, but looking for something really solid as I am circa 180kg (yes, kg not lb!) -

Hence - big wheels, solid frame with no suspension etc and we arrived at the Giant Toughroad SLR1 as a bike of choice.

Picked it up on Sunday and ridden yesterday and today - couple of miles a day - and we have an issue.

I am what you might call a laid back cyclist, I need to sit back firmly on the seat and let my legs do the work - but the seat keeps on slipping - roughly 5cm per mile under we have slipped all the way down - which I can tell you causes a big issue when you have to push 180kg up a hill sitting on a seat in the lowest position :-) (and long legs)

It looks like it's a fancy carbon fibre jobbie - and I can see big scrape marks all the way up where it has slipped!

I don't want to overtighten it - are there any practical things I can do to stop it slipping - it makes the bike very difficult to use! (Which is frustrating as I have really enjoyed the last couple of days - proves one really doesn't forget how to ride a bike!)

Any advice appreciated.

Thanks

Jim

 

[fossyant]

Go get an alloy seat post then if you can't tighten it up. Possibly use carbon assembly paste as the first option.

 

[jimboban]

Thanks Fossyant

I'll speak to the shop to see what they can do - hopefully they will be helpful - but I wanted to gather some opinion before I see what the shop have to say :-)

Cheers

Jim

 

[Tim Hall]

Plus one for the carbon assembly paste. It's plastic granules in greasy stuff. The plastic granules act to increase the friction between the seat post and the seat tube, stopping that sinking feeling.

 

[robgul]

Bike mechanics' eyebrows will be raised and fly half way back over their heads with this - but it does work.

It is a composite seat pin on the bike - replace with a heavy duty alloy one.

Find the absolute optimum position for the saddle height (check, double check, triple check and then check it again) - when happy drill a small hole in the seat tube and through the seat pin about 3" below the seat pin collar and insert a suitable stainless steel self-tapping screw. That will lock the seat pin in position.

Not the best solution BUT it does work - it was performed (by a bike shop) on a classic steel bike frame I had where the integrated seat clamp lugs were bent and the seat bolt wouldn't lock the seat pin sufficiently. The self-tapper is obviously possible to remove if the bike is ridden by a lighter rider or sold.

(I'm expecting all sorts of horror comments about this post!)

Rob

 

[fossyant]

I actually grease my carbon seat post in my alloy frame. It's never slipped but I've got years of experience and don't ever whack up the tightness too much but I am lighter.

The assembly paste will work well - I've never used it, but I had super light alloy bars that would twist easily. I bent them in a crash, so upgraded to super super light alloy ones (same weight as carbon) but they had a gritty clamping surface - it works a treat.

You should either use the paste or grease between surfaces to stop them bonding over time, what ever material.

 

[fossyant]

Bike mechanics' eyebrows will be raised and fly half way back over their heads with this - but it does work.

It is a composite seat pin on the bike - replace with a heavy duty alloy one.

Find the absolute optimum position for the saddle height (check, double check, triple check and then check it again) - when happy drill a small hole in the seat tube and through the seat pin about 3" below the seat pin collar and insert a suitable stainless steel self-tapping screw. That will lock the seat pin in position.

Not the best solution BUT it does work - it was performed (by a bike shop) on a classic steel bike frame I had where the integrated seat clamp lugs were bent and the seat bolt wouldn't lock the seat pin sufficiently. The self-tapper is obviously possible to remove if the bike is ridden by a lighter rider or sold.

(I'm expecting all sorts of horror comments about this post!)

Rob

Not on a new bike under warranty you dont....

 

[Spiderweb]

I would seek advise from the shop you bought it from, if they can't resolve the problem then they could swap the composite for an aluminium stem.

 

[Milkfloat]

You have a fancy 'd fuse' integrated post. These can be a bit of a bugger to get tight without over tightening. I am trying not to be rude but 180kg through a carbon post with d fuse would probably have me checking with Giant if it is wise. I don't think you can get an alloy d fuse post though. One thing you could try is an additional collar to try and stop the slipping. I am thinking one of these

http://www.winstanleysbikes.co.uk/p...UoeujGlSWDB5Z4I7osnvaPkKVlhbJAPsY0aAhZ28P8HAQ

 

[fossyant]

We've had a few big lads on here - Gaz was 39 stone. He started on an MTB for riding, and then was on lightweight road bikes and eventually got down to way less than 100kg, but he is over 6ft.

He is sadly not on the forum any longer, as he has had other medical issues that's stopped him riding. I have been round his house to help sort a nice new carbon bike for him, so it's possible. Gaz has moved way up north so I haven't heard from him for a while.

As has been said, an alloy post might be better as they tolerate clamping better, and most aren't much heavier than carbon !

The LBS should help - If the post slips stop, and get out that allen key. Carbon posts have little benefit over alloy ones.

 

[jimboban]

Thanks Guys

Really appreciate the advice - :-)

I didn't specifically look for a carbon post - just what it came with.

Milk float, particular thanks - I don't know much about bikes but it looks fancy and I did worry it was a bit specialised :-)

Bit nervous about drilling holes in things - not going to give up easy, am sure something will work somehow :-) hopefully that carbon paste stuff might do the job -

I know its just the sheer load going through it - :-)

Cheers

Jim