Can Buying A Smaller Fork Reduce Standover Height?
 

Having bought this bike at auction and finding it just that bit too tall, I was wondering if I bought it a smaller and lighter fork could that drop the standover height of it as if you see in the picture the current fork leaves loads of space to play with.

http://bikeforums.net/attachment.php...hmentid=359194

...bad idea.

what did you buy this bike for? planning on some trails, or did you just need anything to scoot between home and train station ? cause changing the fork enough to make any meaningful standover change will destroy the bike's handling

Nice bicycle! Assuming you got a decent deal... scrub it clean, shine it up like new, and resell it when the weather warms. Take your investment and profit and find another. There are always more bicycles... and better deals.

To ride trails mostly and on road to ride on, but because its big for me I dont trust it very much so just wanted to make it easier to get on and off.

But yes maybe sell it on tho it was a birthday present but its a good bike otherwise, shame really.

Mind you once I get the fork either serviced or upgraded maybe it will ride better as right now it rides a bit like a tank.

Yes its a lot cleaner now than when it was bought when it looked neglected and hard ridden.

Have spent nearly the price it cost on servicing and new parts so far so hopefully will get a new price for it.

It cost £160 and I have spent £120 on new tyres, handlebar grips, chain and sprocket, wheel straightening as well as cleaning products etc.

How much do you think it might sell for just out of interest.

I don't have a clue. I've never deal in £ (only $) and don't know prices in your area.

Would just have to advertise it and see and also see if there are any decent bikes for that price available.

I would take off most of the 'investement' other than maybe the tires and try to sell it,
unfortunately buying new parts at MSRP won't get you much money back on a used bike, may loose you money, the parts you described could be had for £60 from flea bay.
think you are going to loose out on this one, sorry.

To directly answer the OP's question. Yes.

But the amount of straddle height loss will be about 1/2 the amount of fork height change. Then there's the rocking forward of the seat over the cranks, not the best for handling balance or pedaling efficiency. The change in head tube angle will also change the steering feel.

So go ahead and spend more $ to figure out if you're better off getting a bike that fits without making extensive changes. The report back to us with your findings. Andy.

Switch to a 24" front wheel to get the same result.

You screw up the Front end steering Geometry dropping the head tube.
which you do with shorter fork blades. Its long for suspension fork travel.
It does have a suspension fork after all ..

stand over too much ?, get a different bike.

sorry you got such a good price on a wrong sized bike . caveat emptor ..

Sell it or Live with it.

Maybe your Trek dealer will offer a Trade in , used MTB's sell well here

LBS, Here, does trade-ins and Consignments .
dealer Cash buy would be less than A consignment sale.

I was thinking 24" wheels front and rear, but I'm not sure how it would handle in the dirt.

Forgetting all the arguments over whether it's a good idea or not, the simple answer is that it won't change anything.

You can confirm this for yourself by making a stack of books (or whatever) up to a few inches short of your current front axle's height, then putting the fork on it (so simulate the effect of a shorter fork) then either measuring or standing over it.

Since there's no reasonable way to lower the standover height, it's up to you to decide whether to live with it, or consider trading the bike for something smaller (or riding in platform shoes).

If you know someone that has a rigid fork you could borrow swap out your fork and see how it handles. That would give you maybe two inches at the front. I have put rigid forks on suspension bikes with little change in handling, and the opposite.

Thanks for all your advice I will live with it for now and get the suspension serviced when I can, its corroded inside which doesnt help matters :(

When I can afford to replace it I will advertise it and sell it for whatever I can :)

http://for-sale.yakaz.com/trek-3900

Here, it's considered a MTB for beginners.

By the Way there are Rigid non telescoping forks also with, similar long Blades
so the steering Geometry is not deteriorated ..
the term 'suspension corrected' is then applied..

Yes-a fork with LESS TRAVEL- say 63mm vs 100mm- will drop the standover height a bit-maybe 15mm or so 63 to 100mm
What is the travel on that fork?
If you are "handy"-there probably is a way to decrease travel-
You could even go to a rigid fork-maybe $50 used on ebay-it could drop standover as much as 30mm -depending.
Usually-drop travel by 10mm-gets you about 3-4mm lower standover
But change the tires-leave the fork alone-

You can also got to shorter tires-frequently that is simpler- 5mm less sidewall will get you 10mm lower seat height.
I would change tires-you can always use spare tires-spare forks-not as much.
So get lower tires-forget the fork change-
Those tires-pretty tall-45 vs 52-will drop you 1/2 inch-25.2mm per inch-but tires are actually "less wide high" than claimed.

I had a Kona Cinder Cone that the suspension fork was worn out, collapsed. I went to a LBS and got a rigid fork for $1, they had a barrel of take off forks. Worked great handled great, gave it to my son.
Check your LBS, they may have the same, might not be as cheap though!

as you are UK based, look for 'onza rigid' on the bay, Onza in Nottingham have a rigid fork for £18 shipped that is 45mm rake, NOT corrected, so has a 395mm axle to crown height. That would drop the front some depending on your original A-C.
as others have said though, tipping the bike forward like this is likely to make it a bit twitchy.
maybe a shorter stem and sliding the seat back on the rails may get you comfortable again.

SR Suntour XCM w/30mm stanchions, coil spring & preload, 100mm travel.

The wheels are 650b which makes it feel very high tho I think 26" wheels would make it very slow.

Someone asked me if it was a 29er, yeah wish I said lol.

I wouldn't change the wheel size-too expensive- I would literally get smaller diameter tires-generally smaller diameter means shorter sidewalls-lower stand over

It is disc-so you could go to 26" wheels-no they wouldn't be "SLOWER" actually they would accelerate a bit faster-but smaller wheels are slightly less stable
But 26 vs 29-nothing to do with actual speed-and the smaller diameter wheels should allow you to accelerate a bit faster
26 should allow quicker handling-but at the cost of stability.
Folks have done just fine with 26" wheels-so not as if they were falling all over the place
29-700c marketing gimmick of course-no one here is a pro rider-so 26 vs 29-doesn't really matter much-650 same story-gimmick making a comeback

Cost to change over to 24 > selling & buying the right size. I'm sure a others have made this mistake. I bought a 56cm road bike an tried to make it work years ago. I'm 6'4 & ride a 61 - 63 frame. As you can imagine, I sold it after trying different stems, bars, saddles, etc but could never get comfortable. Live & learn.

Unless Trek is doing something funky in the UK that they aren't doing in the US, the wheels aren't 650b. The Trek 3900 listed on the website says the wheels are 26" (ISO 559mm rims). A 29er (ISO 622mm) would only be taller.

As for the fork, you could gain a little bit of standover by going to a shorter travel fork but it will steepen the headtube angle. An a road bike, you might be able to get away with a steeper angle but on a mountain bike used off-road, a steeper head angle makes the bike more difficult to handle. It gets real twitchy when you don't want twitchy.

It's probably best to cut your losses and go to a smaller frame.