Trek Top Fuel geometryMTB · 2025 · 5 sizes, from S to XL

The Trek Top Fuel is a mtb bike available in 5 sizes, from S to XL. Stack ranges from 566 to 626 mm and reach from 422 to 512 mm. Its geometry is low and long, with a racing fit.

Stack566–626mm

Reach422–512mm

Head angle65.9–65.9°

Chainstay length434–444mm

High BBSteep seat angleRacingCalm steering

What size Top Fuel do I need?

Enter the stack and reach of a bike that fits you well and we will tell you which size is closest and how to set it up.

Stack in mm Reach in mm Compare on Fitbikefy →

SS 566 · R 422

MS 599 · R 452

MLS 604 · R 467

LS 608 · R 482

XLS 626 · R 512

Enter your stack and reach to see which size fits you best.

Geometry chart by size

Measurements in mm and degrees, as published by Trek. The ones that matter most for choosing a size are in bold.

Size	S	M	ML	L	XL
Stack	566	599	604	608	626
Reach	422	452	467	482	512
Effective top tube	558	587	611	630	672
Head tube length	105	105	110	115	135
Head angle	65.9°	65.9°	65.9°	65.9°	65.9°
Effective seat angle	76.5°	77.3°	76.6°	76.3°	75.6°
Actual seat angle	69.5°	70.5°	70.5°	70.5°	70.5°
Chainstay length	434	434	439	439	444
Wheelbase	1,150	1,188	1,210	1,227	1,270
Front centre	717	755	772	789	827
BB drop	10	26	26	26	26
BB height	351	354	354	354	354
Fork offset	43	43	43	43	43
Trail	111	121	121	121	121
Standover	705	755	757	758	763
Seat tube (method not stated)	360	410	420	435	470

Source: Trek official website · data from 11 Nov 2026.

Stack and reach of every size

Higher means a taller front end; further right means a longer reach. The blue dot is your search.

Character of each size

Compared with other mtb bikes. Further right means more of that quality.

Positionracing → relaxed

Steeringcalm → quick

Pedallingrearward → forward

Bottom brackethigh → low

Wheelbaselively → planted

Rear endstable → agile

Bikes with similar geometry (size ML)

The closest size of other mtb models, by stack and reach.

ModelΔ stackΔ reach

KTM Scarp Exonic · L2027+3 mm+2 mmCompare →

Wilier Triestina Urta Max SLR · L2027−2 mm+4 mmCompare →

Wilier Triestina Urta Max SL · L2026−2 mm+4 mmCompare →

Trek Supercaliber · L2025−5 mm−2 mmCompare →

BH Lynx SLS · LA2026+5 mm+3 mmCompare →

BH Lynx Race · LA2026−6 mm+3 mmCompare →

Frequently asked questions

What size Top Fuel do I need?

It depends on your position, not just your height. The most reliable way is to compare the stack and reach of a bike that fits you with those of each size (from 566/422 mm in size S to 626/512 mm in size XL). The size finder on this page shows the closest size and the stem and spacers you would need.

What are the stack and reach of the Top Fuel in size ML?

Stack of 604 mm and reach of 467 mm, with an effective top tube of 611 mm and a head angle of 65.9°.

Is the Top Fuel a racing or an endurance bike?

Racing. In size ML its stack-to-reach ratio is at percentile 14 of mtb bikes: a low, stretched position.