Fork_dimension
 

Hi all,

I am new here. I want to fit my bike with a suspension fork. I am very confused on what dimensions I should be looking at to make sure that the fork I am getting will actually fit my bike (I am looking at the classifieds and won't be buying new). My bike is Merida Crossway Urban 20D. General info on the necessary mm will be fine - I will then look into the local offerings and bow to your advise. :giver:

Don't.

Get another bike that is made for suspension forks and already comes with one.

What if I am not in a position to get a new bike? I'm not rich in any way...

You need to first accept that you are voiding the warranty.

Very likely candidates for you are Rock Shox Paragon and Suntour N__ models. Other than those you are likely getting into money to replace some other parts to match.

Make sure that the following match.

• Since you are buying a used fork, the steerer will be cut to length. It needs to be as long as the steerer on your existing fork.
• The headset needs to match size. Some forks have straight 1-1/8" steerers and some have tapered steerers that are 1-1/2" on the bottom.
• The fork needs to be made for your wheel size. Your bike is for 700c commuter/trekking/touring wheels (sometimes called 28") but would also tolerate a fork for 27.5" mountain bikes.
• The dropouts need to match your wheel hub. Most forks have 15mm thru axles, and are now mostly 110 mm wide. Older or cheaper ones will have 9mm quick release and 100mm wide.
• The fork needs to match your brake style. Most forks now are for post-mount disc brakes. Older ones may have IS disk mounts and/or posts further up for rim brakes.
• If some of these don't match you can change the brakes, or the wheel, or so on.

You are GOLD!!! Thank you. This is exactly what I was looking for (and I weren't expecting to get such a swift reply)!!! I bow to you, Dear Sir. :giver:

I'm confident that bike was not designed to take a suspension fork. https://www.merida-bikes.com/en/bike...way-urban-20-d
So it's not possible to make it handle well. You are much better off getting a suspension stem or suspension seat post. I have heard good things about the redshift stem

That bike is not designed for a suspension fork. It will void the warranty, and mess up the way the bike handles.

I don't mean to pile on, but that bike isn't meant for a suspension fork. It's more of a 'fitness hybrid' or 'flat-bar road bike' It might have a straight handlebar and disk brakes, but it's more of a road bike than an MTB or even a trekking bike.

The 'best' fork for your bike would be something like the Suntour NEX, which is intended for '28" hybrids and trekking bikes; However, it's not really found on the kinds of bikes people upgrade a lot, so it might not be easy to find used (although, it's pretty inexpensive new)

The biggest thing you'll find is that when adding a suspension fork onto a rigid bike, it will typically raise the front end of the bike an amount equal or more than the forks' travel; 50-63mm for the NEX, and 100+ mm for a typical MTB fork. This will change the way you fit on the bike, and also change the way the bike handles. This was something we learned in the 1990's when the first forks appeared in MTB, and it accounts for why 90's 'NORBA' bikes don't look like anything that came before or after them.

I actually like a suspension stem on a road bike-based 'path bike' Redshift and KINEKT are the two best options right now. The Redshift is lighter, and less obvious, but the KINEKT has more travel and better tuning options.

[MENTION=543138]Jaaniic[/MENTION] this is a good idea

Don't do it. That bike was not designed for it and you will screw up the whole geometry of the bike which will throw a lot of things off in a bad way. Plus you would void the warranty which you may not have anyway but still. If you are really desperate for more comfort try to fit wider more supple tires run them at lower pressures, find a compatible carbon fork (which will be expensive and not worth it on a heavily Tourney equipped bike) and look at things like the Kinekt seatpost or stem or Redshift ShockStop Stem (however not both stem and seatpost as it will lead to poor fit and really odd riding).

Also I would not even if the bike were suspension ready look at used stuff if you are so unsure because you could be dealing with a lot of sellers who are also unsure and that could lead to a ton of expensive mistakes. The only time I really want a suspension fork is if I am mountain biking or riding generally at higher speeds on a heavy e-bike. I don't want the weight or the energy lose on the road

In the future I would look at a good steel frame or titanium frame which will help smooth out roads. Aluminum on aluminum tends to lead to a stiffer ride and more transfer of vibrations to the rider. Carbon can also be nice depending on how it was constructed some bikes are designed to be super stiff and others designed with a bit of compliance however steel and titanium will generally last forever and some steel can be a little less costly plus I can mount racks and such to steel and titanium whereas with carbon not so much generally.
,.

The bike comes with inexpensive wire bead tires. If comfort is the goal, a slightly wider higher quality tire will be a far better, solution. Also, look into tire pressure, you may be riding at the highest recommended pressure for your tires when you should set the pressure 10 - 20 psi lower. This option costs nothing to try

^ this. The widest, highest volume tire that you can fit within the fork and rear stays, run at the lowest pressure that works for your weight and the terrain. That's your answer right there.

Thanks. I know it is not intended for a suspension fork and that it may make my bike handle worse, but if I do the change and it is very bad - I can always switch back and resell the fork (one of the reasons I don't want to buy new). I was looking at the Suntour NEX myself....that is what Merida fits on their tourism series like standard crossway 20d. My fork extension seems to be 240mm. Can't add photos as a newbie, but the distance from where the fork goes in the frame to the top of the steering wheel. Should be +/- correct :roflmao:

I am not professing you should add a few lbs to the front of your bike just to smooth out the ride. But what you need to know is the axle-crown measurement of your current rigid fork.

However, it may be simpler for you to just contact Merida and find out the frame geometry specs for the Crossway Trekking and the Crossway Urban.

Merida touts the Crossway Trekking as “A perfect blend of comfort, enjoyment and all-round functionality, suitable for fitness training, commuting and leisurely rides through forests and on trails.”

Not to discount the NORBA references but I can’t recall the phrase, “leisurely rides through forests and on trails” in any of their race documentation.

I’m betting both frames are the same.

John

I love advice that goes "run a giant tire at low pressure but don't do a suspension fork, they are heavy and lossy" :p

I still like the suspension stem idea here.

I suggested a slightly wider, better quality tire. We have no idea what sort of tire pressure the OP is using, it may be so high that they can feel every ripple in the road
Still, the suspension stem is an interesting idea as well

The suspension and non-suspension versions of the bike are not the same frame, the suspension version has far less head tube but still nevertheless more stack and less reach - due to the fork.

I really think the fork idea is going to be moot in the end. OP is never going to find a used one with a long enough steerer. It could only come from a comfort bike and who replaces the fork on those? That NEX fork isn't all that great either. My wife's bike is one of those comfort bikes and has one... it's one of the inexpensive and heavy variety, with steel stanchions and a coil spring. Neither of which is dysfunctional, but they do weigh pounds more than aluminum and air. The HLO cartridge is only a lockout, it does not provide any damping. There is a much nicer Suntour fork in this form factor but I can't recall the acronym and don't really care enough to look it up right now, OP won't find it used or want to pay for it new.

if anyone replaces a fork on a bike like this, it's one that came with a suspension fork. Usually they go rigid, but sometimes the old one fails.

I was thinking more about the long-and-low stems that were de rigueur for early 90's hard tails to keep the front ends down, even with the early 50mm forks, like the 150mm-0* ATAC on my Tomac, or the 140mm (-7*) on my Cannondale.
Nothing leisurely about those bikes, though :lol:

[MENTION=543138]Jaaniic[/MENTION]'s Album:

https://www.bikeforums.net/g/user/543138
https://www.bikeforums.net/g/album/22105570

https://cimg1.ibsrv.net/gimg/bikefor...bf47fa9f2.jpeg

I presume this is the bike in question.

The first thing I'd do on the bike is to remove the old fork, and measure the steer tube diameter at the crown race, as well as at the handlebar stem.

I'm wondering if that fork is "tapered", perhaps 1 1/8" at the stem, and 1 1/2" at the crown race.

If it was me, I'd probably try a headshock on that bike.

https://rstsuspension.com/en/forks/c...le-shock/ss-a7
https://rstsuspension.com/en/forks/c...ck/ss-m7-ss-m6

https://rstsuspension.com/images/pro..._up300X900.png

Now, I think the RST forks are only straight tube 1 1/8". If you have a tapered steer tube, you should be able to get away with an adapter for city use.

1) I know nothing about your bike. 2) Most bikes with rigid forks should not be converted to suspension forks - they aren't designed for it. Only convert bikes with forks described as suspension-corrected. 3) Why do you want a suspension fork? Do you ride a lot of bumpy single-track? Maybe a bike designed for your use is a better solution. 4) As others have opined, a suspension stem may be an adequate solution. That's what I did with my MTB. I bought my mid-level MTB in 1988 just before the advent of suspension forks. Sure, the high-end MTBs at the time had them, but mid-line and lower-end bikes did not. I rode that bike for a long time. In fact, I still ride it. In 2005, I did an off-road triathlon on it. The bike leg took about 1 hour but the terrain was so bumpy and uneven that I could hardly hold onto the handlebars by the end of the ride. But I enjoyed that race so much that I thought about upgrading my bike. But I didn't want to upgrade by buying a new bike. I have 4 road bikes and probably do >90% of my riding on them. MTB for me is a diversion. So I researched susp. forks and came to the conclusion that they were not going to work for my bike. Somewhere in my research I stumbled on susp. stems. I ended up buying a used Softride suspension stem on eBay and I do not regret it.