Rigid fork for my shopping bike..

[IDMark2]

Hi,
I thought I'd ask here first for anybody with experience to contribute. I have a Scott P3, I bought it secondhand when I was considering getting back into cycling after my stroke and have since recovered enough to move on to having a faster and lighter road bike as well. I think it's the 2007 model, it's holding up to massive Devon potholes well as a shopping and utility bike and is comfortable to ride through the more rutty lanes we have, I don't really have proper off-road in mind for it.

However, I was considering changing the cheap, heavy and quite frankly used locked-out all the time, Suntour suspension fork with a rigid. I don't think I need to change the headset, it's pretty smooth as it is, but I was wondering what choices would be right in forks to buy, whether I would need to consider geometry of them, trail etc and finally if it was a job I should consider doing myself (I'm fairly competent but that is one area I've not actually done by myself yet) or taking it to my LBS and let them get on with it. It's 700c and V-Brakes.

Thanks for any help.

 

[Pat "5mph"]

Interested in this thread, want to do same

 

[Stantheman]

I was also thinking of ditching my crappy Suntour forks for rigid ones, so I am also interested in this thread.

 

[Cold]

I plan to do the same at some point and have been looking at the Carbon exotic fork but it's £100 so don't know if it is worth it or not.

 

[IDMark2]

I plan to do the same at some point and have been looking at the Carbon exotic fork but it's £100 so don't know if it is worth it or not.

Yes, that does sound a bit posh for mine.. The rear Crudguard I knicked off my old mountain bike is strapped together with duct tape and some of the cable guides are in actual fact zip ties.. one of them even matches the frame colour..

I was more thinking of the £40-50 Cro-moly Planet X ones or similar myself, but I can see the question would be valid for both. We'll see if anyone comes on with some experience of doing similar or we have to pool our stories, which you tube (shudder) videos helped and what we did at some point later on here!

 

[RecordAceFromNew]

Unfortunately those rigid forks from Planet X, and various similar ones from ebay are intrinsically not suitable for you all, if you have 700c suspension forks at present.

One of the critical measures for forks is the axle-to-crown distance (commonly referred to as a2c, and is measured from the centre of the hub axle to where the crown race sits - if you aren't sure where the latter is then the junction between your forks and the headset is close enough). For suspension forks to measure the a2c you can measure it with the forks lifted off the ground and deduct 20% of available suspension travel, or alternatively if it is set up right just the distance when you are sitting on the bike.

The reason those PX and various similar forks for cyclocross (where bikes were never designed to have suspension other than pneumatic tyres in the first place) are unsuitable for you is because they have a2c of c400mm, while yours is likely to be c470mm. 70mm, in fact even 25mm, is a significant enough difference to change the geometry and therefore the handling of your bike noticeably - it will make you feel like you are pitching over the handlebars, and the steering will be very jittery.

For smaller deviations there are various tricks like headset selection or differential tyre size etc. to help manage the effect, but none of which is without issues.

Those eXotic alu or carbon ones are better, they have a2c of 465mm. The question is whether the cost and effort is worth your while for saving c1.5kg assuming steerer configurations etc. are compatible, and whether you are better off selling your bike and add the proceeds to buy a rigid or just a lighter bike, or explore other avenues (e.g. lighter tyres) to lighten up your bike.

Hope it helps.

 

[IDMark2]

Thank you for that @RecordAceFromNew, for me anyway it's less about the weight, the hybrid is never going to be svelte, and more about the gain in rigidity, therefore tracking accuracy and feel, whether actual or imagined. I thought that going without two low quality stanchions and a separate crown and changing to a effectively single component might give gains in those departments. But at least I know where to start as far as measuring and possible cost go, so we're a bit further on. Thanks again for that input.

 

[Crackle]

29er/700c rigid forks exist but they are about 70quid or so. Surly and a few others do them. A2c of 468mm.

http://www.winstanleysbikes.co.uk/p...rks_FKSUKM8K?gclid=CNy8kbGX2b0CFdShtAodsjEABg

Apart from A2C, having never looked at this before, I'd be doing some reading on trail to make sure I didn't dramatically alter that to. Those Surly ones say suspension corrected, I would imagine they'd work but I'd be asking the question here first to see if anyone has done it. It's certainly not unusual to swop to a rigid fork, so having checked the things like trail and a2c and made sure it was 11/8 I had and not some tapered fork (unlikely), I'd be inclined to go for it.

 

[IDMark2]

29er/700c rigid forks exist but they are about 70quid or so. Surly and a few others do them. A2c of 468mm.

Yes, I spotted the Surly Ogre one at cyclestore.uk, thought the same thing as regards a2c (now I look like I know what I'm talking about, look, a2c! oohh..) I guess trail is just what it is, there certainly doesn't seem to be any mention of a figure there. The point is for it to feel different, more agile, responsive and direct I suppose. Whether it will or not is, I suspect, a try it and see...

 

[Crackle]

Yes, I spotted the Surly Ogre one at cyclestore.uk, thought the same thing as regards a2c (now I look like I know what I'm talking about, look, a2c! oohh..) I guess trail is just what it is, there certainly doesn't seem to be any mention of a figure there. The point is for it to feel different, more agile, responsive and direct I suppose. Whether it will or not is, I suspect, a try it and see...

There probably won't be a figure for trail, I don't think it changes much for suspesnsion forks in the same size range. So 'suspension corrected' 700c forks, probably covers it.

I'd measure your own a2c on your bike. In theory they should all be the same, in practice, they'll vary by manufacturer. A 20mm difference in A2c will make about 1 degree of difference in head angle. Follow Recordaces instructions for measuring it.