forks trouble

ZaphodB

Hi - just joined

hopefully some kind soul can help? I apologise in advance for any potential ignorance in these matters..... :?

I recently bought new front forks for my haro EX0 (from about the year 2000) mainly because I was upgrading to disc brakes. The original RST forks didn't have the mounting post/bracket.

The old forks are, I believe RST 281 that came with the bike, the new replacement forks are Suntour SSF245 ?

The problem I've noticed before I fit them are the RST are a certain length with no weight applied, from top of fork (bottom of the headset?) to wheel mounting point.
The new forks are a fair bit longer with no weight applied, and I think it's gonna raise up the front of the bike quite a bit (~10cms)

I just ordered them from 'this bike shop' who also sold me the brakes stuff, they didnt mention there were different length forks available?

Do you think they should have asked the current length and they've sold me the wrong forks for my bike, or will the forks come down to a standard height when fitted and weight is applied.

Can anyone offer advice?

supersonic

Your fork will be longer - though not by 10cm I would imagine. This will slacken the angles somewhat. Fit and see how it feels.

ZaphodB

Sorry I should clarify , the new forks *are longer (unweighted) by the 10cms I mentioned (which is why I'm thnking it'll raise the front of the bike up by those 10cms)

cooldad

Unless you asked them to recommend a replacement fork for your bike, they would have no reason to ask you your current length.

nicklouse

120mm verses 90mm

30mm diference. will slacken the head angle by just over a degree.

cooldad

10cm or 10mm?

ZaphodB

10Cms definitely

nicklouse wrote:

120mm verses 90mm
.

Is this the total travel dimension or something of the two forks?. because I know the RST doesn't have much travel and the new ones have much more.
The RST's sure look like 80/90mm between the bellows, but whilst the suntour's have a 120ish-mm visible clylinder, they have a bit of extra length in the fork itself at the top and also the lower moving cylinder is slightly longer than the RST.
I suppose these extra lengths make up the 10cms I see when I put the forks side by side.

I'm struggling making accurate measurements tonight though, I've lost my tape measure :oops: and am using the scale on the side of a multitool

cooldad

What is the difference from dropout to crown? That's the relevant measurement.

ZaphodB

As said I don't have a tape measure here , I'll borrow one from work and report back tomorrow

ZaphodB

What is the difference from dropout to crown

I'm presuming thats from where the wheel fits (the wheel centre mounting point) up to the top bearing surface of the forks where the bottom of the headset sits?

500mm for the suntours

420mm for the original RST 281 fork that came with the bike

cooldad

That's a big difference. Probably too big, you need shorter forks.

supersonic

See if the shop will change them for an 80mm travel version.

ZaphodB

funnily enough, I was just sorting that and a topic update notification came in on my email

It's a cyclelife (franchise?) shop, and luckily I have just found the receipt too.

Will changing from 120mm to 80mm sort my problem out fully then ?

I kinda liked the idea of the super long travel of these forks, but didn't obviously want this length problem

PS for what it's worth the suntours are described on receipt as SF-XCR 26x1.1